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Biomedical subjects

J L Smith

Publications and source records attributed to J L Smith.

At least 271 records · Page 15Linked to original sources
PubMed1991

Detection of IL-2 at mRNA and protein levels in synovial infiltrates from inflammatory arthropathies using biotinylated oligonucleotide probes in situ.

A non-radioactive in situ hybridization method for IL-2 mRNA detection based on the use of four biotinylated oligonucleotide probes, plus appropriate positive and negative control probes was developed and applied to synovial surgical and needle biopsies from rheumatoid arthritis (RA), spondyloarthropathy (SpA), psoriatic arthritis (PsA) and juvenile chronic arthritis (JCA) patients. In eight surgical biopsies (six RA, one SpA, one PsA) this non-radioactive system showed similar sensitivity to that of a previously described 32P-labelled probe system, and in addition detected IL-2 mRNA in five out of seven biopsies from SpA and PsA patients and in two out of two JCA needle biopsies. IL-2 mRNA was found in the absence of IL-2 protein in RA biopsies (six surgical, 12 needle), but variable amounts of IL-2 protein were detected in six out of seven needle biopsies from SpA, PsA and JCA patients, where CD3+ lymphoid infiltrates were present. These data suggest differences in IL-2 regulation and expression in RA and non-RA inflammatory arthropathies.

Adolescent↗
PubMed1991

No association between susceptibility to multiple sclerosis and HLA-DPB1 alleles in the French Canadian population.

HLA-DPB1 typing was performed using polymerase chain reaction DNA amplification and sequence-specific oligonucleotide probing (PCR-SSOP) which permitted identification of 17 distinct DPB alleles using 15 oligonucleotide probes. The accuracy of this approach was confirmed in an initial study of 26 human B-lymphoblastoid cell lines which demonstrated close agreement between PCR-SSOP and PLT assigned types. A cohort of 47 adult French Canadians was then studied to provide an estimate of DPB1 allelic frequencies in an ethnically homogeneous population. DPB1*0401 was the most frequent phenotype (61.5%) and only DPB1*0101, 0301 and 0402 were also present at frequencies greater than 10%. HLA-DPw4 has been reported to be associated with multiple sclerosis (MS) but our PCR-SSOP analysis of 52 French Canadian MS patients showed no association with either the DPB1*0401 or DPB1*0402 splits of DPw4 or with any other DPB1 allele.

Alleles↗
PubMed1991

HLA DPB1 alleles and susceptibility to rheumatoid arthritis.

HLA-DPB1 genotypic and phenotypic frequencies were investigated in a series of 35 adult rheumatoid arthritis (RA) patients and 42 controls. No significant associations between DPB1 alleles and susceptibility to RA were demonstrated, although some non-significant differences in DPB1*0301 and 0401 allele frequencies between patients and controls were observed.

Alleles↗
PubMed1991

Chronic myelomonocytic leukaemia associated with T cell receptor delta gene rearrangement.

Morphological, immunophenotypic, and genetic analyses were carried out on peripheral blood, bone marrow, and pharyngeal biopsy material from a patient with chronic myelomonocytic leukaemia (CMML). Morphological analysis of bone marrow was diagnostic of CMML; immunophenotypic analysis of peripheral blood and bone marrow were negative for B and T cell antigens, and immunochemistry performed on the pharyngeal extramedullary infiltrate showed the presence of large monocytoid cells which stained positively for muramidase. Genotypic analysis, however, showed clonal rearrangement of the T cell receptor (TCR) delta chain gene, a marker of T cell or, less commonly, B cell lymphoid neoplasms. Other TCR genes, beta and gamma, were germline in all tissues examined. TCR delta is rearranged in precursor B cell and most T lymphoid neoplasms. A small proportion of cases (10%) of acute myeloid leukaemia (AML) also show rearrangement of the TCR delta gene. To date TCR delta rearrangement has not been described in CMML. The aberrant TCR delta rearrangement shown in this patient with CMML provides further evidence of the clonal nature of this disorder.

Bone Marrow↗
PubMed1991

Retinal vasculitis in Lyme borreliosis.

Three patients with retinal vasculitis are reported who were found to be seroreactive for Lyme borreliosis. Careful investigation revealed no other apparent etiology for the angiitis, and improvement of the retinal vasculitis on tetracycline therapy was documented by fluorescein angiography in one of them. Two cases of retinal vasculitis were presented at the International Conference on Lyme Borreliosis in Stockholm 18-21 June 1990, and two cases of cerebral vasculitis due to Borrelia burgdorferi have been published. To our knowledge, this is the first published report of retinal vasculitis occurring in patients seroreactive for Lyme borreliosis. Although further investigation will be necessary to prove a cause-and-effect relationship, ophthalmologists encountering patients with otherwise unexplained cases of retinal vasculitis, or Eales disease, are encouraged to study these patients carefully for the possibility of Borrelia burgdorferi infection.

Adult↗
PubMed1991

Successful combined hepatic and pancreatic allograft retrieval in donors with a replaced right hepatic artery.

The parallel development of reconstructive techniques used to retrieve and transplant organs with vascular anomalies, and of techniques used in the multiple organ retrieval process, have facilitated the recovery of the maximal number of transplantable organs from a limited supply of donors. Recent contributions to this effort are descriptions of combined retrieval of both liver and whole organ pancreaticoduodenal allografts from the same multiple organ donor. Suggested contraindications for the retrieval of the latter allograft have included the presence of a replaced right hepatic artery originating from the superior mesenteric artery. We describe herein the techniques used in retrieving both the liver and the whole pancreas from donors with this vascular anomaly.

Adolescent↗
PubMed1991

Neuro-ocular Lyme borreliosis.

Any patient who has a Bell's palsy (unilateral or bilateral), aseptic meningitis, chronic fatigue syndrome, atypical radiculoneuropathy, presenile dementia, atypical myopathy, or symptoms of atypical rheumatoid arthritis should be asked specifically about the following: visits to highly endemic areas, any known tick bites, any skin lesion suggestive of erythema migrans, any history of palpitations or of prior Bell's palsy, aching in joints (especially the knees), paresthesias, chronic fatigue and depression, forgetfulness, and eye problems. Any patient showing a chronic iritis with posterior synechiae, vitritis in one or both eyes, an atypical pars planitis-like syndrome, big blind spot syndrome, and swollen or hyperemic optic discs should be asked the same questions. The physician should send one red-top tube of blood containing 2 to 3 ml serum to Microbiology Reference Laboratory, 10703 Progress Way, Cypress, CA 90630-4714, requesting a Lyme/treponemal panel. For $90 the patient will receive an RPR test with titer, serum FTA-ABS test, serum Lyme IFA IgG and IgM, and a serum Lyme ELISA test. If these tests are within normal limits and the physician is still suspicious, a Western blot can be ordered on serum. A green top tube with fresh white blood cells sent out by overnight express on a Monday or Tuesday will produce a Lyme PCR and a lymphocyte stimulation test. Finally, R.K. Porschen, director of MRL Laboratory, will provide information on the urine antigen test on an investigational basis. A careful history with emphasis on the specific questions noted above, a complete neuro-ophthalmological and physical examination ruling out other causative problems, and the laboratory studies here discussed will usually provide sufficient data to choose therapy. Much further active research into Lyme borreliosis is an important priority in medicine.

Adult↗
PubMed1991

An investigation of T-cell subset phenotype and function in the rheumatoid synovium using in situ hybridization for IL-2 mRNA.

Cryostat sections of synovial biopsy tissue from patients with active rheumatoid arthritis (RA), spondyloarthritis (SpA) and osteoarthritis (OA) have been investigated for interleukin-2 (IL-2) mRNA and protein production. In situ hybridization using 32P-labelled oligonucleotide probes based on IL-2 gene sequences coded by exon 1 and exon 3 of the IL-2 gene revealed IL-2 mRNA over lymphoid aggregates in RA and SpA tissue. No IL-2 mRNA was detected in OA tissue and reflected the absence of lymphoid infiltrates in these tissues. Total mRNA, as detected by a 32P oligo dT probe, was found in all tissue examined. IL-2 protein product was detected by monoclonal antibody staining in SpA but not in RA or OA tissue. This is the first report of in situ studies of lymphoid function in the microenvironment of the RA synovium. Whether these data reflect the function of normal CD3+ CD4+ CD45RO+ T-cell subsets in the diseased joint remains to be resolved.

Aged↗
PubMed1990

Crystallization and preliminary X-ray investigation of lipoxygenase 1 from soybeans.

Soybean lipoxygenase 1 has been crystallized by the vapor diffusion method in 8-10% polyethylene glycol (average Mr 3400), 0.2 M sodium acetate buffer, pH 5.2-5.6, at a protein concentration of 6-12 mg/ml. Microseeding was employed to obtain growth of large single crystals. The crystals, which diffract to at least 2.2-A spacings, are monoclinic and of space group P2(1). Cell constants are: a = 95.4, b = 94.2, and c = 50.4 A and beta = 91.4 degrees. The calculated value of Vm (2.41 A3/Da) is consistent with the probable presence of one molecule of lipoxygenase/crystallographic asymmetric unit (Z = 2).

Chemical Phenomena↗
PubMed1990

A probability representation for phase information from multiwavelength anomalous dispersion.

A probability distribution function, cast in the representation of Hendrickson & Lattman [Acta Cryst. (1970), B26, 136-143], has been derived for the phase information from measurements of multiwavelength anomalous diffraction (MAD). This probability function readily permits one to determine figure-of-merit weights similar to those used in isomorphous replacement, and the coefficients that characterize this distribution function facilitate the combining of MAD phasing with results from other sources of phase information. This probability representation was derived in the course of a structural analysis of selenobiotinyl streptavidin from MAD data and applications have also been made in the structure determinations of interleukin-1 alpha and a drug complex with brominated DNA.

Bacterial Proteins↗
PubMed1990

Eperythrozoon wenyonii infection in dairy cattle.

Approximately 10 of 100 young heifers that had recently delivered their first calf--members of a large Colorado dairy herd--had a syndrome of swollen teats and distal portions of the hind limbs, prefemoral lymphadenopathy, transient fever, rough coat, decreased milk production, and subsequent weight loss and reproductive inefficiency. Acute clinical signs of disease were associated with large numbers of Eperythrozoon wenyonii seen on blood smears, and resolution of signs correlated with reduction or disappearance of the parasite. Other known causes of peripheral edema could not be documented. The parasite was transmitted to 4 of 7 nonlactating dairy cows destined to be culled and a splenectomized calf via IV inoculation of blood from parasitemic heifers, but clinical signs of infection were not induced.

Anaplasmataceae Infections↗
PubMed1990

Crystallization and preliminary X-ray analysis of beta-hydroxydecanoyl thiol ester dehydrase from Escherichia coli.

Escherichia coli beta-hydroxydecanoyl thiol ester dehydrase, a key enzyme for the biosynthesis of unsaturated fatty acids in E. coli, has been crystallized by the vapor diffusion method at pH 5.0-5.5 using 20% (w/v) polyethylene glycol (molecular weight 8000) as a precipitant. Two crystal forms have been characterized, and both diffract to at least 1.6 A. The orthorhombic crystals belong to space group P2(1)2(1)2(1), with cell constants of a = 68.4 A, b = 87.3 A, and c = 60.3 A. Monoclinic crystals are of space group C2, with a = 131.9 A, b = 71.5 A, c = 92.5 A, and beta = 103.5 degrees.

Crystallization↗
PubMed1990

What happens to tablets and capsules in the stomach: endoscopic comparison of disintegration and dispersion characteristics of two microencapsulated potassium formulations.

Previously we investigated gastric emptying and distribution of a capsule formulation of microencapsulated KCl and found the drug was usually present in clumps of KCl crystals held in place by gastric mucus. We therefore investigated whether a tablet formulation of microencapsulated KCl would have improved dispersion. We characterized the intragastric disintegration of capsules and tablets of microencapsulated KCl in 12 subjects. The capsule formulation floated in the gastric pool; one end would adhere to the gastric mucosa and the motion of the tethered capsule would pull the end of the capsule off. The KCl crystals would then be deposited in a mass. In contrast, the tablet formulation sank to the anatomically most dependent portion of the stomach. The tablet rapidly became soft and fragile but, if allowed to remain in one place and minimally disturbed, required a median of 12 min to lose its shape. If allowed to reach the gastric antrum, the tablet was quickly ground by the antro-pyloric pump and widely dispersed. Once liberated in the stomach, the microencapsulated KCl crystals were bound into a more-or-less cohesive mass. The differences between KCl formulations, once the crystals were released, was minimal although the larger crystals from the tablet formulation appeared less adherent and cohesive; they dispersed more in a reticulated pattern when the stomach was distended. We conclude that formulation of a drug in a microencapsulated multiple-unit dosage form does not guarantee wide dispersion nor absence of high local concentration of drug.

Adult↗