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Biomedical subjects

J Jackson

Publications and source records attributed to J Jackson.

At least 19 recordsLinked to original sources
PubMed1992

Low-molecular weight B cell growth factor (BCGF-12KD) as an autocrine growth factor in B cell chronic lymphocytic leukemia.

The role of cytokines in the growth and spreading of human hematologic malignancies has been underlined in recent years. Here we report evidence that a human 12-kDa B cell growth factor (BCGF-12KD) may function as a growth stimulatory factor in B cell chronic lymphocytic leukemia (B-CLL). First, recombinant BCGF-12KD induced dose-dependent DNA synthesis in neoplastic B cells of four B-CLL patients tested. Second, seven different B-CLL clones secreted a BCGF-12KD-like product that accounted for their proliferation. A neutralizing monoclonal antibody (mAb; Ac8) directed against a BCGF-12KD synthetic peptide inhibited the spontaneous growth of the leukemic B cells. The same mAb blocked DNA synthesis in normal tonsillar B lymphocytes induced by the culture supernatant of spontaneously proliferating B-CLL cells. Finally, BCGF-12KD mRNA was expressed in freshly isolated (two of three patients) as well as in vitro proliferating B-CLL cells (three of three patients). These findings strongly suggest that BCGF-12KD can modulate the growth of B-CLL cells in vivo as well as in vitro. They may offer significant insights into the biology of this frequent B lymphoproliferative disorder.

Adult↗
PubMed1992

Chemical and immunological testing for faecel occult blood: a comparison of two tests in symptomatic patients.

An established chemical faecal occult blood test (Haemoccult prepared without rehydration) has been compared with a new immunological test (Hemeselect) in patients referred for investigation of lower gastro-intestinal symptoms. Hemeselect was shown to have a higher sensitivity for colorectal carcinoma (94.0% compared with 58.0%), the greatest difference in sensitivity between the two tests being for rectal cancers. Similarly Hemeselect was more sensitive than Haemoccult for colorectal adenomas (66.6% vs 33.3%), and for inflammatory bowel disease (88.9% vs 33.3%). However the enhanced sensitivity of Hemeselect for colorectal neoplasia and inflammatory bowel disease was accompanied by a significant increase in the overall rate of positive reactions (32.8% of patients had a positive Hemeselect reaction compared with 14.8% who had a positive Haemoccult test), and a reduction in specificity (84.1% for Hemeselect vs 96.0% for Haemoccult). Hemeselect is a more sensitive indicator of colorectal neoplasia in symptomatic subjects, trials of its use as a screening test for asymptomatic neoplasia appear justified.

Adenoma↗
PubMed1992

The intraoperative localization of the obscure bleeding site using fluorescein.

Despite visceral angiography and radiolabeled gastrointestinal scintigraphy, the localization of gastrointestinal bleeding can still be a challenge. Even preoperative localization with visceral angiography is no guarantee of successful intraoperative localization or subsequent pathological confirmation. We report a case of obscure gastrointestinal bleeding of small bowel origin, which was localized intraoperatively by fluorescein injected via a superselectively placed catheter.

Angiography↗
PubMed1992

Psoriasis, psoriatic arthritis and the possible association with Sjögren's syndrome.

Thirty patients with psoriatic arthropathy (PA) were age- and sex-matched with patients with plaque psoriasis alone to investigate a possible link between Sjögren's syndrome (SS) and PA. The results of clinical examination, Schirmer's test, maximal stimulated salivary flow rate, haematological and serological investigations were compared in the two groups. Median maximal stimulated salivary flow rate was significantly reduced in patients with PA suggesting that salivary glands are affected in this condition. One patient with PA had SS.

Adult↗
PubMed1992

Value of scintigraphic localization of obscure gastrointestinal bleeding.

A total of 51 technetium-99m (99mTc)-labelled autologous red cell (LRC) scans performed on 49 patients for the localization of obscure gastrointestinal bleeding over a 5-year period was reviewed. The sensitivity for LRC scanning was 72.7% with a positive predictive value of 84.2%. Forty patients underwent both LRC scanning and visceral angiography during the same admission; angiography had a sensitivity of 38.9% compared with 66.7% for LRC scanning and the positive predictive values were 77.8% and 85.7%, respectively. Overall, the site of bleeding was located in 22 (45%) of 49 patients, but LRC scanning alone was successful in identifying the lesion in 16 (33%) cases. In patients who continue to bleed to the point of requiring operation, a combination of scintigraphy and angiography will localize a source in 70% of patients.

Aged↗
PubMed1992

Anti-IL-6 antibodies suppress myeloid cell production and the generation of CFU-c in long-term bone marrow cultures.

Interleukin 6 (IL-6) is one of several hemopoietic growth factors produced by stromal cell lines derived from the adherent layer of long-term bone marrow cultures (LTBMCs). To evaluate the potential role of IL-6 in stromal cell-dependent myelopoiesis, we established LTBMCs and verified that IL-6 mRNA is transcribed by heterogeneous adherent cell layers and that IL-6 protein is present in culture supernatants. Established LTBMCs were then depleted of IL-6 by using a specific neutralizing monoclonal antibody (mAb). Cultures treated for 2-3 weeks with anti-IL-6 mAb showed decreased production of maturing myeloid cells and colony-forming progenitor cells (colony-forming units in culture, CFU-c) but not stem cells (spleen colony-forming units, CFU-s). In parallel experiments, it was also found that the addition of IL-6 to LTBMCs stimulated a marked increase in total cell production, CFU-c, and day-8 CFU-s. In sum, it appears that endogenous production of IL-6, although limiting, is essential for the normal level of myelopoiesis associated with stromal cell function in LTBMCs.

Animals↗
PubMed1992

Selection of patients with the antiphospholipid syndrome by serological measurement of lupus anticoagulant activity in conjunction with anticardiolipin antibodies.

The significance of anti-cardiolipin antibodies (ACLA) in patients with a range of autoimmune and infective disorders was investigated in this study. Although lower levels of IgG and IgM ACLA were present in 77 of 400 patients' sera (19%), high antibody levels were found in less than 5% of patients. These latter patients belonged to three clinical categories: patients with connective tissue disease (CTD), infectious mononucleosis or biological false positive serology. An assay was developed to measure lupus anticoagulant (LA) activity in serum: significant LA activity was found in the CTD patients alone (in 6 of 15 tested) and all of these had high titre ACLA. Features of the antiphospholipid syndrome (APS) were present in these six patients but also in three additional CTD patients with normal LA results and high levels of ACLA. In two CTD patients with APS features, the high ACLA were of IgM isotype. These results stress the importance of measuring both ACLA and LA in an investigation of the APS: a high positive ACLA supports the diagnosis of APS, particularly in patients with autoimmune disease, whilst a high positive ACLA in association with LA activity is specific for this syndrome.

Antibodies, Antinuclear↗
PubMed1991

Determination of neomycin in plasma and urine by high-performance liquid chromatography. Application to a preliminary pharmacokinetic study.

A reversed-phase high-performance liquid chromatographic (HPLC) method has been developed for the determination of neomycin in plasma and urine. The plasma was deproteinated with trichloroacetic acid and centrifuged. The supernatant was mixed with ion-pair concentrate and centrifuged again. The resultant supernatant was analyzed by HPLC. Urine was centrifuged to remove debris, if any, mixed with ion-pair concentrate and analyzed directly by HPLC. The HPLC conditions consisted of an ion-pairing mobile phase, a reversed-phase column, post-column derivatization with o-phthalaldehyde (OPA) reagent and fluorescence detection. The overall average recovery of neomycin was 97 and 113% from plasma spiked at 0.25-1.0 micrograms/ml, using standard curves prepared in plasma extract and in water, respectively, and 94% for urine spiked at 1-10 micrograms/ml using a standard curve prepared in water. The method was used to detect neomycin in plasma and urine obtained from animals injected intramuscularly with neomycin. Various pharmacokinetic parameters of neomycin were also determined from its profile of plasma concentration versus time.

Animals↗
PubMed1991

Loneliness and psychological distress.

Research on relationships between loneliness and psychological symptoms has generally shown significant positive associations across a wide spectrum of psychopathologies. However, such results may be artificial, to some extent, given the high intercorrelations of typical psychopathology measures. In the current study, we examined associations between psychological symptoms, assessed by the Symptom Check List-90 (SCL-90; Derogatis, Lipman, & Covi, 1973) and loneliness, as measured by the UCLA-R Loneliness Scale (Russell, Peplau, & Cutrona, 1980), in college students. Using partial correlations to control for the confounding influence of generalized distress, relationships between loneliness and individual dimensions of distress were examined. Results indicate a significant association between loneliness and interpersonal sensitivity (low self-esteem) and depression. Other dimensions of distress were not significantly related to loneliness. In addition, no sex differences in patterns of association were observed. Results support the notion that self-blame and self-devaluation are strong correlates of loneliness.

Adaptation, Psychological↗
PubMed1991

Clinical comparison of the resin-containing BACTEC 26 Plus and the Isolator 10 blood culturing systems.

The new resin-containing BACTEC 26 Plus blood culturing system (Becton Dickinson Diagnostic Instrument Systems, Towson, Md.) was compared with the Isolator 10 system (Wampole Laboratories, Cranbury, N.J.). Blood samples were drawn by syringe, and equal 10-ml volumes were evaluated in each blood culture system by the recommended methods. Both systems were incubated aerobically with 5% CO2. Of 11,506 acceptable study specimens, 1,788 aerobic isolates were recovered. Overall, recoveries was similar for the two systems, with 626 bacteria or fungi recovered in the BACTEC 26 Plus system only, 499 recovered in the Isolator system only, and 663 recovered in both systems. Of 345 gram-negative rods, 62 grew in the BACTEC system only and 109 grew in the Isolator system only (P less than 0.001). Thirty-three of these Isolator-only gram-negative organisms were Acinetobacter spp. Of 209 yeasts, 38 grew in BACTEC only and 81 grew in Isolator only (P less than 0.001). Of 200 streptococci and enterococci, 98 were recovered in BACTEC only and 26 grew in Isolator only (P less than 0.001). Two hundred twenty-eight independent episodes of gram-negative rod bacteremia occurred. Isolator was the first system positive in 59 of 197 episodes, compared with 45 of 197 for BACTEC when Acinetobacter episodes were excluded. Times to detection were similar for the two systems. High colony counts correlated with repeat positive blood cultures. Isolator and BACTEC had similar overall recoveries, with individual merits and deficiencies for both systems. The additional quantitative information derived from Isolator had utility in our institution.

Bacteremia↗
PubMed1991

A gene related to the proto-oncogene fps/fes is expressed at diverse times during the life cycle of Drosophila melanogaster.

The proto-oncogene fps/fes encodes a distinctive type of protein-tyrosine kinase. We identified a Drosophila gene (dfps85D) whose product resembles the proteins encoded by vertebrate fps/fes and the closely related gene fer. dfps85D is located at chromosomal position 85D10-13 and is unlikely to correspond to any previously defined genetic locus in Drosophila melanogaster. Expression of the gene is entirely zygotic in origin and occurs throughout the life cycle. But hybridization in situ revealed that the pattern of expression is specialized and evolves in a provocative manner. The most notable feature of expression is the diversity of developmental periods, tissues, and cells in which it occurs. In some tissues, expression is transient; in others, it is continuous. Expression occurs in both mitotic and terminally differentiated tissue and, at various times in development, is prominent in imaginal disks, gut, muscle, testes, ovaries, retina, and other neural tissues. It appears that the use of dfps85D is more diversified than that of other Drosophila protein-tyrosine kinases reported to date and contrasts sharply with the restricted expression of fps itself in vertebrates. The detailed description of expression provided here will help guide the search for mutants in dfps85D.

Amino Acid Sequence↗
PubMed1991

Telling the truth.

Are doctors and nurses bound by just the same constraints as everyone else in regard to honesty? What, anyway, does honesty require? Telling no lies? Avoiding intentional deception by whatever means? From a utilitarian standpoint lying would seem to be on the same footing as other forms of intentional deception: yielding the same consequences. But utilitarianism fails to explain the wrongness of lying. Doctors and nurses, like everyone else, have a prima facie duty not to lie--but again like everyone else, they are not duty-bound to avoid intentional deception, lying apart; except where it would involve a breach of trust.

Beneficence↗