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Biomedical subjects

A Solomon

Publications and source records attributed to A Solomon.

At least 181 records · Page 10Linked to original sources
PubMed1991

Anterior capsule adherence to iris leading to pseudophakic pupillary block.

We present a rare case of anterior capsule adherence to the iris following extracapsular cataract extraction with posterior chamber intraocular lens implantation and leading to pseudophakic pupillary block. There were no synechiae at the pupillary margins associated with the capsule/iris adherence, but aqueous was entrapped behind the iris and intraocular pressure rose. Laser iridotomy was temporarily beneficial, but it had to be repeated several times.

Aged↗
PubMed1991

Computerized tomographic recognition of visceral pleural changes.

Pathology of the visceral pleura seen by CT of the lung can be separated from the underlying lung parenchyma by using appropriate CT window viewing settings. A wide window setting permits both pleura and lung parenchyma to be examined simultaneously. The use of mediastinal window setting (i.e., soft tissue) showed the smooth inner surface of parietal pleural fibrosis or plaque formation lying parallel or convex to the associated rib cage, whereas the thickened or calcified visceral pleura had an irregular inner surface with single or multiple protrusions penetrating the underlying lung substance and retraction of the associated pathological visceral pleural surface. We present cases of tuberculous calcified visceral pleura, a talc pleuritis and carcinoma abutting on the interlobar fissure, and clearly demonstrate the CT features.

Calcinosis↗
PubMed1991

Intravitreal suture: a complication of pterygium surgery.

Among the complications associated with pterygium surgery, scleral perforation is mentioned in cases where subconjunctival tissue must be separated from the sclera. We present a case in which such a perforation and consequent suturing resulted in an intravitreous migration of a suture. We believe this is the first report of such a complication following pterygium surgery.

Female↗
PubMed1990

Growth of injured rabbit optic axons within their degenerating optic nerve.

Spontaneous growth of axons after injury is extremely limited in the mammalian central nervous system (CNS). It is now clear, however, that injured CNS axons can be induced to elongate when provided with a suitable environment. Thus injured CNS axons can elongate, but they do not do so unless their environment is altered. We now show apparent regenerative growth of injured optic axons. This growth is achieved in the adult rabbit optic nerve by the use of a combined treatment consisting of: (1) supplying soluble substances originating from growing axons to be injured rabbit optic nerves (Schwartz et al., Science, 228:600-603, 1985), and (2) application of low energy He-Ne laser irradiation, which appears to delay degenerative changes in the injured axons (Schwartz et al., Lasers Surg. Med., 7:51-55, 1985; Assia et al., Brain Res., 476:205-212, 1988). Two to 8 weeks after this treatment, unmyelinated and thinly myelinated axons are found at the lesion site and distal to it. Morphological and immunocytochemical evidence indicate that these thinly myelinated and unmyelinated axons are growing in close association with glial cells. Only these axons are identified as being growing axons. These newly growing axons transverse the site of injury and extend into the distal stump of the nerve, which contains degenerating axons. Axons of this type could be detected distal to the lesion only in nerves subjected to the combined treatment. No unmyelinated or thinly myelinated axons in association with glial cells were seen at 6 or 8 weeks postoperatively in nerves that were not treated, or in nerves in which the two stumps were completely disconnected. Two millimeters distal to the site of injury, the growing axons are confined to a compartment comprising 5%-30% of the cross section of the nerve. A temporal analysis indicates that axons have grown as far as 6 mm distal to the site of injury, by 8 weeks postoperatively. Anterograde labeling with horseradish peroxidase, injected intraocularly, indicates that some of these newly growing axons arise from retinal ganglion cells.

Animals↗
PubMed1990

Monoclonal immunoglobulin deposition disease: light chain and light and heavy chain deposition diseases and their relation to light chain amyloidosis. Clinical features, immunopathology, and molecular analysis.

Monoclonal immunoglobulin deposition occurs in tissues as Congo Red binding fibrils in light chain amyloidosis, as less structured deposits in light chain deposition disease, and as similar but distinct deposits in light and heavy chain deposition disease. The nonamyloid forms were found in 13 patients who had evidence of plasmacytic dyscrasia by the immunohistochemical detection of immunoglobulin light chains of kappa or lambda class (with or without staining for a single heavy chain isotype) and by the absence of amyloid P component in tissue sections that did not show the birefringence characteristic of amyloid after Congo Red staining. All but two of the patients presented with proteinuria with or without azotemia. Clinical syndromes involving other organ systems were less common but occasionally severe. Four patients had overt multiple myeloma. Three others had hypercalcemia and mild bone marrow plasmacytosis but no lytic lesions. Analyses of immunoglobulin synthesis in bone marrow cells from seven patients showed excess light chains in all and incomplete light chains or heavy chain fragments in six, regardless of whether an intact monoclonal protein or related subunit was in the serum or urine. The fibrillar (amyloidotic) and nonfibrillar forms of monoclonal immunoglobulin deposition occur either in overt multiple myeloma or in the course of less neoplastically aggressive plasmacytic dyscrasias. Bone marrow cells from patients with either type produce immunoglobulin fragments that are related to those deposited in the affected tissues.

Adult↗
PubMed1990

Direct coronal CT scanning of tracheo-bronchial, pulmonary and thoraco-abdominal lesions in children.

Direct coronal plane CT demonstration of the tracheobronchial and pulmonary anatomy is possible. Large gantry openings easily accommodate patients in a sitting or semiprone position without the need for attaching a seat device to the table top. A technique is described for examining the patient using Elscint 1800 and 2400 CT units, with a net gantry angulation of 60-80 degrees to the chest, with resulting good quality direct coronal CT imaging. Our experience includes more than a hundred pediatric patients that have been examined, displaying diverse tracheobronchial, pulmonary and thoraco-abdominal lesions. The technique is safe and comfortable to the patients and is easy to perform.

Adolescent↗
PubMed1990

Immunoglobulin heavy-chain-associated amyloidosis.

Immunoglobulin- or multiple myeloma-associated amyloidosis has been distinguished by the tissue deposition of Congophilic, fibrillar protein consisting of light chains or light-chain fragments (AL amyloidosis). We now report the isolation and characterization of another form of immunoglobulin-associated amyloid obtained from a patient who had extensive systemic amyloidosis and in whom the amyloid deposits consisted not of light chains but rather of an unusual form of heavy chain. This component, isolated from splenic amyloid extracts, represented an internally deleted IgG1 heavy chain as evidenced by immunochemical, electrophoretic, and amino acid sequence analyses. A comparable immunoglobulin-related monoclonal protein, consisting only of IgG heavy chains, was present in the patient's urine. Based on serologic reactivity with a battery of anti-immunoglobulin antisera, these two immunoglobulin-related components were antigenically identical; however, when compared to normal IgG, both were deficient in Fc-associated gamma-chain determinants. The structural abnormality of the amyloid gamma-chain protein was further evidenced by SDS/PAGE and immuno-blotting analyses: An unusually low molecular mass of approximately 22 kDa was found for this material vs. the expected value of approximately 55 kDa for a normal gamma heavy chain. Despite the lack of certain Fc determinants, the amyloid and urinary heavy-chain proteins expressed the IgG1 subclass allotype marker G1m(a) located on the third constant region (CH3) domain of the internally deleted IgG1 heavy chains. That the amyloid protein contained an intact CH3 domain was established through amino acid sequence analyses of cyanogen bromide fragments and peptides generated by a lysine-specific protease. These studies also revealed that the gamma-chain amyloid protein contained the complete heavy-chain variable (VH) domain [including the diversity (DH) and joining (JH) segments] that was contiguous with the CH3 domain. The low molecular mass of the protein resulted from the total absence of the first (CH1), hinge, and second (CH2) heavy-chain constant regions. Such extensive CH deletions and the presence of a complete VH distinguish this amyloid-associated heavy chain from all other heretofore characterized gamma-heavy-chain disease proteins. This heavy-chain-related form of immunoglobulin-associated amyloidosis is tentatively designated AH amyloidosis.

Aged↗
PubMed1990

Pathogenic anti-DNA antibodies in SLE: idiotypic families and genetic origins.

We have adopted an idiotypic approach to study the double stranded DNA (dsDNA) binding antibodies of systemic lupus erythematosus (SLE). Three anti-idiotypic reagents, 8.12, 3I, and F4, identify cross reactive idiotypes that are each expressed on anti-dsDNA antibodies in the sera of many patients with SLE. These idiotypic antibodies are implicated in the pathogenesis of SLE as they are present in immune complex deposits in the kidneys of patients with SLE glomerulonephritis. The autoantibody associated idiotypes are also expressed on antibodies that do not bind DNA. We are investigating the origin of the pathogenic anti-dsDNA antibodies of SLE by comparing the autoantibodies, the antibodies to foreign antigens, and the myeloma proteins that express each SLE associated idiotype. In conjunction with serological analysis of these idiotypic systems, molecular genetic studies indicate that both the 8.12 and the 3I autoantibody associated idiotypes may be germline encoded, while the F4 idiotype is generated by somatic mutation. The data further suggest that the antigenic specificity of the pathogenic anti-DNA antibodies of SLE is acquired through somatic mutation of germline immunoglobulin genes. By studying the regulation of genes capable of encoding pathogenic autoantibodies, in both SLE patients and non-autoimmune individuals, we may be able to elucidate the pathogenesis of autoimmune disease and begin to design more effective therapeutic interventions.

Antibodies, Antinuclear↗
PubMed1990

Immunocytochemical detection of kappa and lambda light chain V region subgroups in human B-cell malignancies.

We have used a sensitive immunoperoxidase method and highly specific anti-light chain antisera to determine the light chain variable region (VL) subgroup nature of cytoplasmic (c) and cell surface (s) Ig expressed by human monoclonal plasma cells and B lymphocytes. The immunocytochemical characterization of cIg and sIg used antisera specific for the established kappa light chain V kappa subgroups (V kappa I, V kappa II, V kappa III, and V kappa IV) and the lambda light chain V lambda subgroups (V lambda I, V lambda II/V, V lambda IV, and V lambda VI). Studies were performed using cytospin preparations of bone marrow-, peripheral blood-, and lymph node-derived cells from patients with multiple myeloma, amyloidosis AL, and Waldenström's macroglobulinemia and with low-, mid-, and high-grade B-cell malignancies. The V kappa or V lambda subgroup of the cIg or sIg also could be identified after deparaffinization and enzyme treatment of formalin-fixed, paraffin-embedded specimens. For those patients who had monoclonal serum or urinary Igs, there was complete concordance between the VL subgroup of the secreted Ig and that of the cIg or sIg. The percentage distribution of V kappa or V lambda subgroups on the sIg of cells from patients with chronic lymphocytic leukemia (CLL) and other cytomorphologic types of B-cell malignancies differed from that found for kappa- or lambda-type Bence Jones proteins obtained from patients with multiple myeloma, amyloidosis AL, and Waldenström's macroglobulinemia. In contrast to the plasma cell and lymphocytoid plasma cell diseases, a relative predominance of certain VL subgroups, ie, V kappa IV, V lambda III, and V lambda IV, and the absence of the amyloid-associated V lambda VI subgroup were found in CLL and related diseases. The immunocytochemical techniques used make possible a rapid means to demonstrate B-cell monoclonality and provide further evidence for the selective expression of certain VL genes in human B-cell neoplasia.

Amyloidosis↗
PubMed1990

Multiple myeloma in pregnancy: a case report.

We report here a 33-year-old patient found at 20 weeks' gestation to be anemic and to have both a serum M-protein (immunoglobulin [Ig]G kappa) and a kappa-type urinary Bence Jones protein. The concentration of these proteins, measured during pregnancy and in the postpartum period, demonstrated the presence of the maternal serum IgG kappa component in the amniotic fluid and its transmission to, and eventual disappearance from, the newborn.

Bence Jones Protein↗
PubMed1989

Failure of T cell receptor V beta negative selection in an athymic environment.

The mature T cell receptor (TCR) repertoire is the result of selection events during T cell development. Previous assessment of TCR beta-chain selection with serologic and molecular probes demonstrated both positive and negative selection. Although this work suggested a critical role for the thymus, no direct assessment has been made of the requirement for a thymus in TCR V beta selection. A comparison of TCR V beta expression in four different congenic pairs of normal and nu/nu (athymic) mice indicated that the normal V beta deletions associated with tolerance to self minor lymphocyte stimulating (Mlsc) antigens or to self major histocompatibility complex (MHC)-encoded E alpha E beta products did not occur in most athymic mice. Thus, the thymus has a critical role in mediating self tolerance by negative selection.

Animals↗
PubMed1989

A cross-reactive idiotype on anti-DNA antibodies defines a H chain determinant present almost exclusively on IgG antibodies.

We have previously reported two anti-idiotypic antibodies, 3I and 8.12, that recognize L chain determinants on anti-DNA antibodies. We have generated a new anti-idiotypic antibody, F4, that recognizes a H chain determinant on cationic anti-DNA antibodies. F4 reactivity is present in high titer in serum of approximately 60% of SLE patients and on 84 of 706 myeloma proteins. It is preferentially associated with 3I reactive L chains. Furthermore, antibodies bearing both the F4 and 3I idiotypic determinants preferentially bind DNA. Amino acid sequencing of H chains isolated from four F4-reactive myeloma proteins suggests that they derive from two currently identified VH gene families. F4 reactivity is restricted almost exclusively to Ig of the IgG isotype suggesting that F4 may recognize either a somatically mutated hypervariable region or a variable region used late in the immune response. F4, therefore, represents a new idiotypic family preferentially associated with auto-Ag specificity and having features of an Ag-driven immune response.

Amino Acid Sequence↗
PubMed1989

Structure of a second crystal form of Bence-Jones protein Loc: strikingly different domain associations in two crystal forms of a single protein.

We have determined the structure of the immunoglobulin light-chain dimer Loc in a second crystal form that was grown from distilled water. The crystal structure was determined to 2.8-A resolution; the R factor is 0.22. The two variable domains are related by local 2-fold axes and form an antigen binding "pocket". The variable domain-variable domain interaction observed in this crystal form differs from the one exhibited by the protein when crystallized from ammonium sulfate in which the two variable domains formed a protrusion (Chang et al., 1985). The structure attained in the distilled water crystals is similar to, but not identical with, the one observed for the Mcg light-chain dimer in crystals grown from ammonium sulfate. Thus, two strikingly different structures were attained by this multisubunit protein in crystals grown under two different, commonly used, crystallization techniques. The quaternary interactions exhibited by the protein in the two crystal forms are sufficiently different to suggest fundamentally different interpretations of the structural basis for the function of this protein. This observation may have general implications regarding the use of single crystallographic determinations for detailed identification of structural and functional relationships. On the other hand, proteins whose structures can be altered by manipulation of crystallization conditions may provide useful systems for study of fundamental structural chemistry.

Bence Jones Protein↗
PubMed1989

Structural and idiotypic characterization of the L chains of human IgM autoantibodies with different specificities.

We have determined the V region amino acid sequence and/or serologic markers (kIIIb, PSL2, and PSL3) of 24 IgM monoclonal autoantibodies with specificities of anti-gamma-globulin (RF), anti-I (cold agglutinin), anti-low density lipoprotein and anti-intermediate filaments. The data emphasize the overwhelming selection of the HumKv325/VkIIIb L chain for this family of autoantibodies. The few amino acid substitutions found within the VL regions were mainly concentrated in the complementarity-determining region 1. JK and CK genes did not show the same pattern of restriction. There is a good correlation between the amino acid sequence and the presence of the kIIIb marker. The idiotypic marker PSL2 was present in 34 out of 35 kIIIb L chains analyzed (97%) and the PSL3 in 27 (80%). Moreover, the hydrophilicity and antigenic profiles of these L chains corroborate the presence of the epitopes detected by the anti-CRI. These results demonstrate a restricted selection of the Vk genes used by a family of self reacting proteins, and an unusual evolutionary conservation of the idiotypic structure that may be involved in the network regulation.

Agglutinins↗
PubMed1989

Stannosis. A report of 2 cases.

Stannosis is a condition in which tin-oxide is deposited in lung tissue after inhalation. Tin-oxide is radiologically visible although there is no tissue reaction to its presence. Two examples of the condition are described. It is of value to recognise the condition and so avoid unnecessary invasive diagnostic procedures.

Humans↗
PubMed1989

Temporal parameters of low energy laser irradiation for optimal delay of post-traumatic degeneration of rat optic nerve.

Compression injury of a central nerve results in its degeneration with irreversible loss of function due to the inability of the mammalian central nervous system (CNS) to regenerate. In contrast, the CNS of lower vertebrates has a high capacity to regenerate. Recently, low energy laser irradiation was shown to attenuate degeneration in injured CNS nerves. The optic nerves of rats were subjected to moderate crush, calibrated so that some electrophysiological activity was preserved. The nerves were then subjected to low energy laser irradiation (10.5 mW, 2 min daily) for various periods. The electrical activity of the nerves, distal to the site of injury, was determined by measuring the compound action potential at the termination of the experiment. Two weeks of irradiation begun immediately after injury and continued daily thereafter, resulted in a compound action potential which was significantly higher (mean +/- S.E.M. 1856 +/- 535 microV) than that of non-irradiated injured nerves (351 +/- 120 microV). The effect was temporary and subsided within a week. This two-week irradiation was slightly more effective than a treatment lasting one week (1406 +/- 225 microV) and was significantly more effective than 4 days of irradiation (960 +/- 133 microV). The number of treatments is therefore important. The time at which the treatment commences relative to the injury is also critical. Irradiation initiated two hours after the crush was about half as effective as immediate irradiation (810 +/- 42 microV). No apparent effect was evident when the laser was applied for the first time 5 h, or longer, after the crush.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Cell division in the healing of the corneal endothelium of cats.

The pattern of cell division of the corneal endothelium of cats was studied during the first week following scraping of 35.2% to 38.3% of the endothelial cells. A small number of mitoses were found 2 days after scraping (mean +/- SD, 8.2 +/- 6.1 per cornea); the number peaked during the third and the fourth days (148.5 +/- 74.5 and 206.8 +/- 40.1, respectively), sharply decreased on the fifth day to a level of 17.0 +/- 9.5, and further decreased on the sixth and seventh days to 4.2 +/- 1.8 and 3.3 +/- 1.5 mitoses per cornea, respectively. Due essentially to amitotic cell division, a multinuclear cell population, mainly binuclear, appeared and increased to a number of 3999 +/- 746 and 3,129 +/- 877 on the sixth and seventh days, respectively, after scraping. Thus, mitotic and amitotic cell division is an integral part of the posttraumatic regeneration process of the corneal endothelium of cats.

Animals↗