Search PubMed⌕ Search

Biomedical subjects

B J Luft

Publications and source records attributed to B J Luft.

At least 73 records · Page 4Linked to original sources
PubMed1991

An overview of the problem of toxoplasmosis and pneumocystosis in AIDS in the USA: implication for future therapeutic trials.

By the end of 1989, 18,518 cases of Pneumocystis carinii infection and 5,614 cases of Toxoplasma gondii infection were reported to the Centers for Disease Control as the AIDS indicator disease. Pneumocystosis did not vary according to gender, race or risk factors; whereas toxoplasmosis was more common in black males with no known risk factors. Immigrants to the USA from Africa, Latin America and Haiti are three to four times more likely to develop toxoplasmic encephalitis than American-born patients with AIDS. The implications of this epidemiologic data for the predictive value of serology and clinical trials are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Treatment of acute toxoplasmosis with intravenous clindamycin. The California Collaborative Treatment Group.

The interim results are presented of an ongoing large-scale, prospective, randomized study to determine the potential role of clindamycin in the treatment of toxoplasmic encephalitis. Patients were seropositive for Toxoplasma gondii antibodies and had clinical signs compatible with toxoplasmic encephalitis. Data was available on 33 patients, 15 of whom received pyrimethamine p.o./clindamycin i.v. and then p.o., and 18 of whom received pyrimethamine p.o./sulfadiazine p.o. The interim evaluation did not reveal a remarkable difference between the two regimens in the clinical or radiologic response. Adverse reactions to both regimens were common and frequently multiple, there being more adverse gastrointestinal reactions in patients on pyrimethamine/clindamycin and more adverse hematological reactions in those on pyrimethamine/sulfadiazine.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Mapping antibody-binding domains of the major outer surface membrane protein (OspA) of Borrelia burgdorferi.

The major outer surface membrane protein of Borrelia burgdorferi, OspA, is one of several antigens recognized by sera from some patients in the chronic phase of Lyme borreliosis. We have expressed the OspA open reading frame in Escherichia coli and generated a series of deletion constructs of the gene and expressed them as trpE fusion proteins in E. coli. These constructs were used to identify antibody-binding sites of both rabbit antiserum and mouse monoclonal antibodies (MAbs) directed against OspA. All antibodies tested failed to bind to a fusion protein containing the first 61 amino acids of OspA, suggesting that the amino-terminal domain of OspA is unexposed to the cell surface. The binding site for one MAb, 184.1, was identified in a region centered around amino acid 61, while the binding site for MAb 105.5 was identified in a region centered around amino acids 214 to 217. Sera from two patients which were reactive to OspA identified distinct epitopes that lie between those recognized by our MAbs.

Animals↗
PubMed1990

Amoxycillin plus probenecid versus doxycycline for treatment of erythema migrans borreliosis.

72 adults with erythema migrans (early Lyme borreliosis) were enrolled in a randomised prospective trial comparing amoxycillin 500 mg plus probenecid 500 mg three times a day with doxycycline 100 mg twice a day for 21 days. These antibiotic regimens were chosen because of the known in-vitro sensitivity of Borrelia burgdorferi, the antibiotic tissue penetration, the pharmacokinetics of the drugs, and because the organism can disseminate early in the course of infection. 72 patients were evaluable (35 in the doxycycline group and 37 in the amoxycillin/probenecid group). The two regimens were equally effective for treatment of erythema migrans. Mild fatigue or arthralgia were the only post-treatment complaints, which resolved within 6 months. None of the patients needed further antibiotic treatment for Lyme borreliosis.

Adult↗
PubMed1990

Cross-antigenicity between the major surface proteins (ospA and ospB) and other proteins of Borrelia burgdorferi.

Two of the major surface Ag of Borrelia burgdorferi, the 31-kDa OspA and 34-kDa OspB proteins, are encoded by a 49-kb plasmid. In this study, mAb and monospecific polyclonal antibodies were used to define cross-antigenicity of the OspA and OspB protein to each other and to other lower molecular mass proteins by Western blot analysis. Two mAb studied, 105.5 and 184.1, were directed predominantly against the 31-kDa OspA protein. However, each also reacted with other minor bands, though with different specificities. Using V8 protease digestion and cleavage by cyanogen bromide, we demonstrated that each mAb reacted to the 31-kDa protein differently. Monospecific polyclonal rabbit and human antibodies directed against the 34-, 31-, 22-, and 20-kDa proteins were eluted from blots and used to further corroborate the cross-reactivity among these Ag. Rabbit antibodies to the 31- and 22-kDa Ag gave remarkably similar peptide maps after V8 protease digestion of the 31-kDa OspA protein, as did mAb 184.1, suggesting that this mAb recognized an immunodominant epitope common to the 22- and 31-kDa proteins. It seems likely therefore that the humoral immune response to Borrelia surface Ag may be due to a limited number of cross-reactive epitopes on distinct, but related, gene products.

Antibodies, Bacterial↗
PubMed1990

Lyme neuroborreliosis. Peripheral nervous system manifestations.

An ever increasing number of apparently unrelated peripheral nervous system (PNS) disorders has been associated with Lyme borreliosis. To ascertain their relative frequency and significance, we studied prospectively 74 consecutive patients with late Lyme disease, with and without PNS symptoms: 53% had intermittent limb paraesthesiae, 25% the carpal tunnel syndrome, 8% painful radiculopathy, and 3% Bell's palsy; 39% had disseminated neurophysiological abnormalities. To assess the interrelationships among these syndromes, we reviewed the neurophysiological findings in all 163 such patients that we have studied to date. Reversible abnormalities of distal conduction were the most common finding. Demyelinating neuropathy was extremely rare. The pattern of abnormality was similar in all patient groups, regardless of whether the symptoms suggested radiculopathy, Bell's palsy, or neuropathy. We conclude that (1) reversible PNS abnormalities occur in one-third of our patients with late Lyme borreliosis, and (2) the pattern of electrophysiological abnormalities is the same in all and is indicative of widespread axonal damage, suggesting that these different presentations reflect varying manifestations of the same pathological process.

Adolescent↗
PubMed1990

Penicillin-binding proteins in Borrelia burgdorferi.

Penicillin-binding proteins were identified in Borrelia burgdorferi membranes. A 94-kilodalton penicillin-binding protein was the first to be labeled with tritiated penicillin and was the first band to disappear in a competition experiment. Its binding ability was destroyed when membranes were preboiled. In addition, several of these penicillin-binding proteins comigrated with bands previously identified as surface proteins.

Bacterial Proteins↗
PubMed1989

Carpal tunnel syndrome in Lyme borreliosis.

Neurophysiologic evidence of median nerve entrapment in the carpal tunnel was present in 25% of patients with late Lyme borreliosis. Sixty-eight of 76 consecutive, prospectively studied patients with late Lyme underwent neurophysiologic testing. Nineteen reported intermittent hand paresthesias; 17 had neurophysiologically confirmed carpal tunnel syndrome. This was not consistently associated with clinically apparent wrist arthritis or with neurophysiologically evident peripheral neuropathy. We conclude that a significant proportion of patients with late Lyme borreliosis develop carpal tunnel syndrome.

Adult↗
PubMed1989

Antibiotic treatment of Lyme borreliosis.

Unlike most bacterial infections, where diagnosis is by identification of the causal organism, diagnosis of infection by Borrelia burgdorferi (Lyme's borreliosis) relies mostly upon indirect techniques. This situation has some short-comings. As long as no technology permits a microbiological diagnosis of this infection, controversy will exist as to the clinical symptoms and the criteria for the cure of the disease. Despite the lack of consensus upon both the clinical definition and the treatment of Lyme's borreliosis, it is widely agreed that the affection is best understood if regarded as a progressive general infectious disease. Indeed, following a bite with local infection, there occurs a fairly rapid dissemination of the spirochaetes. In vivo therapeutic trials have shown the potential effectiveness of beta-lactams and tetracyclines, but no treatment is considered universally effective. Most of the first trials were empirical, as antibiograms were not used. Antibiotic concentrations reached with some oral therapies are too low for the protection of certain sites such as the central nervous system. In vitro studies conducted on various strains of B. burgdorferi both in the US and in Europe are very enlightening. Among the more perplexing results of some of these studies, it is worth noting the high resistance rate of some B. burgdorferi strains to penicillin, reported by Johnson et al. and by Preac Mursic et al. Therapy for Lyme's borreliosis is discussed in light of both the in vivo and in vitro studies.

Borrelia↗
PubMed1989

Biochemical and immunological characterization of the surface proteins of Borrelia burgdorferi.

The immunodominant proteins and glycoproteins of Borrelia burgdorferi were analyzed by one-dimensional (1D) and 2D gel electrophoresis. More than 100 polypeptide species could be detected on silver-stained 2D gels. Separation of sonic extracts of the organism by differential centrifugation (100,000 X g) revealed several of the major proteins to reside predominantly within the pellet fraction. The antigenicity of the individual polypeptides was determined by Western (immuno-) blot analysis with sera from humans with chronic Lyme disease and from rabbits immunized with B. burgdorferi. Surface proteins of viable B. burgdorferi labeled with 125I or long-arm hydroxysuccinimide biotin were identified by gel analyses. Thirteen major surface proteins were apparent, including the highly immunogenic 41-kilodalton (kDa) endoflagellar antigen. Two of these proteins, with molecular masses of 22 and 41 kDa, were further characterized by electroblotting and microsequencing their amino termini. Significant (35%) homology between the first 20 amino acids of the 22-kDa protein and the deduced amino acid sequence of the 31-kDa (outer surface protein A) protein of B. burgdorferi may indicate that these proteins are processed similarly or are part of a gene family expressed at the surface of the organism. In addition, highly significant (88%) homology was found between the first nine amino acids of the 41-kDa protein of B. burgdorferi and the 33-kDa endoflagellar protein of Treponema pallidum, after which the sequences diverge. This observation provides in part a structural basis for the observed cross-reactivity between the two organisms and suggests alternative approaches to the development of specific immunodiagnostics.

Amino Acid Sequence↗
PubMed1989

Lyme neuroborreliosis: central nervous system manifestations.

We evaluated 85 patients with serologic evidence of Borrelia burgdorferi infection. Manifestations included encephalopathy (41), neuropathy (27), meningitis (2), multiple sclerosis (MS) (6), and psychiatric disorders (3). We performed lumbar punctures in 53, brain MRI in 33, and evoked potentials (EPs) in 33. Only patients with an MS-like illness had abnormal EPs, elevated IgG index, and oligoclonal bands in the cerebrospinal fluid. Twelve of 18 patients with encephalopathy, meningitis, or focal CNS disease had evidence of intrathecal synthesis of anti-B burgdorferi antibody, compared with no patients with either MS-like or psychiatric illnesses, and only 2/24 patients with neuropathy. MRIs were abnormal in 7/17 patients with encephalopathy, 5/6 patients with an MS-like illness, and no others. We conclude that (1) intrathecal concentration of specific antibody is a useful marker of CNS B burgdorferi infection; (2) Lyme disease causes an encephalopathy, probably due to infection of the CNS; (3) MS patients with serum immunoreactivity against B burgdorferi lack evidence of CNS infection with this organism.

Acute Disease↗
PubMed1989

Treatment of Lyme borreliosis.

The infectious process of Lyme disease can appear as chronic dermatologic, rheumatologic, or neurologic. To rationally select a treatment regimen, the physician must have an appreciation of the clinical manifestations of the illness and of the systemic nature of the infection. The authors discuss the proper treatment protocols for each stage in the progression of Lyme disease.

Anti-Bacterial Agents↗
PubMed1989

Lyme borreliosis.

Explore the source record for details and available documents.

Acute Disease↗
PubMed1989

Immunodiagnosis of Lyme borreliosis.

The clinical definition of Lyme disease depends on the epidemiologic association of signs and symptoms with a measureable immune response to B. burgdorferi. The dependence on the demonstration of an immune response to B. burgdorferi has made the understanding of this systemic spirochetosis critical for the physician when making a diagnosis.

Antibodies, Bacterial↗
PubMed1988

Seronegative Lyme disease. Dissociation of specific T- and B-lymphocyte responses to Borrelia burgdorferi.

The diagnosis of Lyme disease often depends on the measurement of serum antibodies to Borrelia burgdorferi, the spirochete that causes this disorder. Although prompt treatment with antibiotics may abrogate the antibody response to the infection, symptoms persist in some patients. We studied 17 patients who had presented with acute Lyme disease and received prompt treatment with oral antibiotics, but in whom chronic Lyme disease subsequently developed. Although these patients had clinically active disease, none had diagnostic levels of antibodies to B. burgdorferi on either a standard enzyme-linked immunosorbent assay or immunofluorescence assay. On Western blot analysis, the level of immunoglobulin reactivity against B. burgdorferi in serum from these patients was no greater than that in serum from normal controls. The patients had a vigorous T-cell proliferative response to whole B. burgdorferi, with a mean ( +/- SEM) stimulation index of 17.8 +/- 3.3, similar to that (15.8 +/- 3.2) in 18 patients with chronic Lyme disease who had detectable antibodies. The T-cell response of both groups was greater than that of a control group of healthy subjects (3.1 +/- 0.5; P less than 0.001). We conclude that the presence of chronic Lyme disease cannot be excluded by the absence of antibodies against B. burgdorferi and that a specific T-cell blastogenic response to B. burgdorferi is evidence of infection in seronegative patients with clinical indications of chronic Lyme disease.

Adolescent↗