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Biomedical subjects

I Steiner

Publications and source records attributed to I Steiner.

At least 91 records · Page 5Linked to original sources
PubMed1993

Complete heart block and seizures in an adult with systemic lupus erythematosus. A possible pathophysiologic role for anti-SS-A/Ro and anti-SS-B/La autoantibodies.

OBJECTIVE: To determine the serum autoantibody profile in an adult patient with systemic lupus erythematosus manifested by complete heart block (CHB) and seizures, and to investigate the source of autoantibodies found in the patient's cerebrospinal fluid (CSF). METHODS: The serum and CSF autoantibody profiles were determined by serologic testing and Western blot studies. An antibody activity index was devised to determine the source of the autoantibodies found in the CSF. RESULTS: The patient's serum contained anti-SS-A (52 kd and 60 kd), anti-SS-B, anti-U1 RNP, and anti-Sm autoantibodies. Studies of her CSF, however, revealed only anti-SS-A and anti-SS-B autoantibodies, with a high antibody activity index. CONCLUSION: The finding of anti-SS-A (52 kd and 60 kd) and anti-SS-B autoantibodies was similar to reported findings in congenital CHB. Intrathecal synthesis of anti-SS-A and anti-SS-B was the source of autoantibodies found in the CSF. This patient's symptoms may be pathophysiologically linked to an immune reaction between the anti-SS-A and anti-SS-B autoantibodies and neural tissue in the brain and heart.

Adult↗
PubMed1993

Molecular biology of herpes simplex virus type 1 latency in the nervous system.

Herpes simplex virus (HSV) is one of the best studied examples of viral ability to remain latent in the human nervous system and to cause recurrent disease by reactivation. Intensive effort was directed in recent years to unveil the molecular viral mechanisms and the virus-host interactions associated with latent HSV infection. The discovery of the state of the latent viral DNA in nervous tissues and of the presence of latency-associated gene expression during latent infection, both differing from the situation during viral replication, provided important clues relevant to the pathogenesis of latent HSV infection. This review summarizes the current state of knowledge on the site of latent infection, the molecular phenomena of latency, and the mechanisms of the various stages of latency: acute infection, establishment and maintenance of latency, and reactivation. This information paved the way to recent trials aiming to use herpes viruses as vectors to deliver genes into the nervous system, an issue that is also addressed in this review.

Acute Disease↗
PubMed1993

Characterization of an in vivo reactivation model of herpes simplex virus from mice trigeminal ganglia.

Herpes simplex virus type 1 (HSV-1) is transcriptionally active during latent infection in human peripheral sensory ganglia. Viral gene expression includes the latency-associated transcripts (LATs) which have been linked to the ability of the virus to resume replication and reactivate. However, the molecular basis of reactivation and the mechanisms of action of these transcripts are unknown. In order to study these parameters, an in vivo reactivation model is needed. We investigated use of the mouse as the experimental animal, modifying the route of infection, the viral strain and the reactivation protocol. Following administration of human immunoglobulin 1 day prior to corneal infection, no infectious virus was detected in trigeminal ganglia (TG). However, latency was established in all infected animals as indicated by explant reactivation of TG, and in vivo reactivation was achieved in 30 to 40% of them. DNA quantification revealed that TG of immunized mice contained more HSV-1 DNA than did those of non-immunized mice. By in situ hybridization twice as many neuronal cells in TG of immunized mice were positive for LATs, compared with infected but non-immunized, mice. These findings suggest that suppression of primary infection facilitates reactivation by increasing HSV-1 copy number in latently infected nervous tissue.

Animals↗
PubMed1993

The use of herpes simplex virus vectors for gene therapy in neurological diseases.

Herpes simplex virus type 1 (HSV-1) vectors have now been developed and enable the efficient delivery of foreign genes under the control of appropriate promoter elements into non-dividing neurons in vitro and in vivo. Their use is based on the natural ability of HSV-1 to spread throughout the nervous system and to establish a lifelong latent infection in neurons. HSV is present in an episomal form in the neuronal nucleus, and normal neuronal functions remain unaltered. A wide variety of foreign genes can theoretically be packaged into the large HSV genome. A number of technical problems will need to be overcome to ensure the stable expression of the foreign gene products, adequate control of the levels of their expression, the safety of the vectors and the correct targeting of the vectors to the appropriate neuronal cell populations. Such vectors have the potential to replace missing gene products in neurons in patients with a variety of metabolic and neurodegenerative diseases, and also to insert growth factors or enzymes into the local vicinity of neurological lesions to promote neuronal repair. HSV-1 vectors also have the potential to define the genetic basis of various neurophysiological functions which may prove to be useful in evaluating altered neuronal function encountered in disease.

Gene Transfer Techniques↗
PubMed1993

[Nonbacterial thrombotic endocarditis--a study of 171 case reports].

A descriptive term nonbacterial thrombotic endocarditis (NBTE) is used currently instead of the former name marantic endocarditis. The study describes 171 cases of NBTE encountered in autopsies over a period of 22 years (an incidence of 0.93% in adults). Malignancy was present in 59% of cases. Tumors relatively most frequently associated with NBTE were carcinomas of the ovaries, biliary system, pancreas, lung, and stomach. The vegetations were located mostly on the left-sided valves (mitral 64%, aortic 24%, both 9%). The involved valves were otherwise normal in 82%, and they were previously damaged in 18%. Systemic emboli from valvular vegetations occurred in 41% of patients, with splenic, cerebral, and renal circulations being most frequently affected. Pulmonary embolism was noted in 43%. The state of nutrition at autopsy was within normal limits in 35%; there was undernourishment or cachexia in 40%, and overweight or obesity in 22% of patients. The main pathogenetic factor in NBTE seems to be a state of hypercoagulation.

Adult↗
PubMed1993

[Mycoses of the heart].

There is an increasing frequency of heart mycoses. Authors identified 19 such cases between 1972 and 1991, 63% in the last 6 years (frequency was 0.1% in 17.661 autopsies of patients over 7 days of life). Males prevailed (17:2). Yeasts of genus Candida dominated, unusual etiology represented Candida parapsilosis, Torulopsis candida and Aspergillus restrictus. Sampling from vegetations or abscesses was a prerequisite for positive autoptic cultivation. Probable source of infection was found in 12 patients and 5 of them had an infected thrombosis of venous catheter. Mycosepsis comprised nearly equal number of endocarditides (mostly left sided) and myocarditides. Spread of endocardial infection into myocardium was rare, most myocarditides resulted from disseminated infection in immunocompromised patients. Endocarditides mainly complicated surgical interventions.

Adolescent↗
PubMed1992

Neurologic manifestations of progressive systemic sclerosis.

Neurologic involvement in progressive systemic sclerosis is considered uncommon. We retrospectively examined the prevalence and nature of neurologic complications in 50 patients with progressive systemic sclerosis. In 20 (40%), neurologic abnormalities were detected, with a total of 28 neurologic manifestations. All levels of the central and peripheral nervous system were affected: muscle (22%), peripheral nerve (18%), spinal cord (8%), and brain (6%). Of note were the presence of myelopathy in four patients and inclusion-body myositis in two. In 10 patients (20%), no definable cause of the neurologic dysfunction could be identified, apart from progressive systemic sclerosis. Thus, neurologic presentations of progressive systemic sclerosis are much more common than previously reported and may be due to direct involvement of the nervous system by a primary pathologic process in a significant number of patients.

Adult↗
PubMed1992

Multifocal motor nerve conduction abnormalities in amyotrophic lateral sclerosis.

Motor nerve conduction in motor neuron disease is considered normal until the terminal stages of the disease, a notable exception being lower motor neuron syndrome associated with anti-glycolipid antibodies. We reviewed the electrophysiological findings in all our patients who were diagnosed as having amyotrophic lateral sclerosis (ALS) during the last 6 years. Six patients, clinically indistinguishable from "classical" ALS patients, out of 31 (19%) displayed motor nerve conduction abnormalities. The most consistent finding, occurring in all 6, was prolonged distal latency or reduced conduction velocity in the distal segment of the median nerve, with normal sensory conduction, suggesting possible pressure proneness of motor nerve fibers in ALS. Additional abnormalities included multifocal motor conduction slowing (3 patients), and conduction blocks (4 patients). None of the patients had paraproteinemia and anti-GM1 and anti-GD1a antibodies were not detected. Thus, a subgroup of clinically indistinguishable ALS patients may have multifocal motor nerve conduction abnormalities, indicating motor nerve fiber involvement. The etiology and pathogenesis of the peripheral nerve involvement are presently unknown.

Adult↗
PubMed1991

Hereditary branching enzyme dysfunction in adult polyglucosan body disease: a possible metabolic cause in two patients.

We describe 2 unrelated patients with adult polyglucosan body disease (APBD) diagnosed by sural nerve biopsy. Both patients were offspring of consanguineous marriages. They presented clinically with late onset pyramidal tetraparesis, micturition difficulties, peripheral neuropathy, and mild cognitive impairment. Magnetic resonance imaging of the brain revealed extensive white matter abnormalities in both. In search of a possible metabolic defect, we evaluated glycogen metabolism in these patients and their clinically unaffected children. Branching enzyme activity in the patients' polymorphonuclear leukocytes was about 15% of control values, whereas their children displayed values of 50 to 60%, suggesting a possible autosomal recessive mode of transmission. This is the first report of an inherited metabolic defect in patients with adult polyglucosan body disease. We suggest that branching enzyme dysfunction may be implicated in the pathogenesis of some patients with adult polyglucosan body disease.

1,4-alpha-Glucan Branching Enzyme↗
PubMed1991

[The effect of terephthalic acid and foils made of polyterephthalic acid esters on fat soluble vitamins].

The effect of terephthalic acid, which is found in foodstuffs as a monomer of fat-soluble vitamins such as vitamin A, D3 and alpha-tocopherol was examined in model tests of terephthalic acids, and of foils composed of polyterephthalic acid esters. Vitamin A and D3 were stabilized by terephthalic acid (the vitamin content was up to 25% after adding terephthalic acid, depending on temperature and duration of heating); alpha-tocopherol was reduced a little faster with terephthalic acid. Heated in the foil the vitamin content was not reduced as much as in the model tests with terephthalic acid.

Cholecalciferol↗
PubMed1991

Seronegative myasthenia gravis: clinical features, response to therapy and synthesis of acetylcholine receptor antibodies in vitro.

Circulating autoantibodies against the acetylcholine receptor (AChR-Ab) are an important diagnostic tool in myasthenia gravis (MG). Lack of antibodies may cast doubt upon the diagnosis, the immune-mediated mechanism and the nature of the antigen. We examined clinical and laboratory features, response to immunotherapy and production of AChR-Ab in vitro, in 12 seronegative MG patients who were followed up for 2-30 years. It was possible to divide those patients into 2 groups: 7 patients with systemic muscle weakness, with a severe disease and with response to immunosuppressive therapies. The other group of 5 patients was characterized by oculobulbar symptomatology, a relatively benign course and immunotherapy was ineffective in 3 treated patients. Five patients underwent thymectomy and gland histology was normal in all of them. In none of 9 patients examined, were AChR-Ab synthesized in vitro (compared to 65% of seropositive myasthenic patients). Thus seronegative generalized MG is probably an autoimmune disease though the autoantigen is presently unknown and is responsive to immunosuppressive treatment. Seronegative oculobulbar MG might represent a separate disease entity in which immunological mechanisms play no significant role.

Adolescent↗
PubMed1991

The HSV-1 latency associated transcript (LAT) variants 1704 and 1705 are glycoprotein C negative.

The latency associated transcripts (LAT) of herpes simplex virus type 1 (HSV-1) are encoded by diploid genes that are expressed during latent infections. Two LAT variant viruses, 1704 and 1705, were compared with the parental strain 17+. Variant 1705 has a deletion affecting one copy of the LAT genes, expresses LATs during latent infection and reactivates normally. Variant 1704 has deletions affecting both LAT gene copies, does not express LATs during latent infection, and its reactivation is impaired (Steiner et al., 1989). Comparison of infected cell proteins by immunoprecipitation and Western blot analysis revealed one significant difference between HSV-1 strain 17+, 1704 and 1705; glycoprotein C (gC) was not synthesized by 1704 or 1705. Since both 1704 and 1705 are gC minus, the reactivation defect of 1704 is most likely related to the absence of the LATs, and not to the absence of gC.

Animals↗