Biomedical subjects
Publications and source records attributed to J M Jones.
We report five children with transverse defects of the upper limb who developed calcified deposits at the distal end of the limb. The lesions were excised from two children and had the typical histological appearance of tumoral calcinosis but on clinical grounds it is unlikely that this is the same condition as that previously described as tumoral calcinosis.
We have compared, in a double-blind study, the efficacy of topical amethocaine cream 1 g (5% w/w) in alleviating the pain of venous cannulation with that of 5% EMLA cream 2.5 g. One hundred and twenty unpremedicated female patients undergoing minor gynaecological surgery, were allocated randomly to one of four groups: 5% EMLA cream 2.5 g for 30 min: 5% EMLA cream 2.5 g for 60 min; amethocaine cream 1 g (5% w/w) for 30 min; amethocaine cream 1 g (5% w/w) for 60 min. After removal of the cream, venous cannulation was performed with an 18-gauge cannula. Patients assessed the pain experienced using a 100-mm visual analogue score and four-point rank score. In addition, a blinded observer assessed the patient's response to venous cannulation using a four-point rank score. Good analgesia was obtained in all groups and there was no statistically significant difference in pain scores between the groups.
WI-1, a 120-kD protein found in the outer cell wall of Blastomyces dermatitidis, has been purified, labeled with 125I, and used as a target in a radioimmunoassay (RIA). In an assessment of the usefulness of anti-WI-1 serology in the diagnosis of blastomycosis, the RIA was used to test four panels of sera from residents of Wisconsin, a state in which blastomycosis is endemic. Twenty-four (75%) of 32 patients whose blastomycosis had been reported to the Wisconsin Division of Health had at least one serum sample positive for antibody to WI-1; 25 (93%) of 27 serum samples obtained from these patients within 60 days of diagnosis were positive. In an effort to simulate clinical practice, 132 serum samples were assayed from another 107 patients in whom blastomycosis was being considered as a cause of illness. The result was positive for at least one sample from 83% of the 23 patients with confirmed blastomycosis and from 5% of the 84 patients from whom the fungus was not documented. Serum samples from another five patients with blastomycosis identified during investigation of a 1990 outbreak in Oconto Falls, Wisconsin, also gave a positive result, whereas none of the serum specimens from 57 healthy family members or neighbors did so. Only three (0.56%) of 535 serum samples from random blood donors residing in two counties with a high annual incidence of blastomycosis were positive for antibody to WI-1. Modification of the RIA so that IgM rather than IgG antibody was detected did not enhance diagnostic sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)
The molecular basis for pathogenicity and virulence of the dimorphic fungus Blastomyces dermatitidis remains unknown. WI-1 is a major cell wall protein of B. dermatitidis yeasts and is a recognition target of both humoral and cell-mediated immunity. As an initial study to determine if WI-1 might be linked to virulence of B. dermatitidis, we quantified WI-1 expression on three genetically related strains that differ in their virulence for mice: wild-type virulent ATCC strain 26199, mutant ATCC strain 60915 (which is 10,000-fold reduced in virulence), and mutant ATCC strain 60916 (which is avirulent). Two principal alterations in WI-1 expression were observed in the mutants. First, the mutants express more WI-1 on their surface, as quantified by flow cytometry with monoclonal antibody to WI-1 and by radioimmunoassay, but the WI-1 on their cell wall is less extractable than that on the wild-type strain. Second, the mutants shed less WI-1 during culture and demonstrate impaired processing of shed WI-1. Surface alterations in WI-1 were accompanied by significant differences in the binding of the virulent and mutant strains to human monocyte-derived macrophages. Attachment of yeasts to macrophages paralleled and was proportional to the expression of WI-1. Compared with wild-type yeasts, both mutants bound to macrophages more rapidly and in two- to threefold-greater magnitude. Furthermore, about 75% of yeast binding to macrophages was inhibited by a Fab anti-WI-1 monoclonal antibody. These results suggest that altered WI-1 expression on attenuated and avirulent mutant B. dermatitidis yeasts greatly facilitates macrophage recognition and binding of yeasts and, in turn, may contribute to more rapid ingestion and killing in the host.
The lack of well-defined antigens from Blastomyces dermatitidis has hampered the ability to reliably diagnose human infection and study the immunobiology of blastomycosis. We recently discovered a novel surface protein on B. dermatitidis yeasts, designated WI-1, and demonstrated it to be a key antigenic target of humoral and cellular responses during infection. In the present article, we purified and characterized WI-1 and compared it immunologically with the only Blastomyces antigen commercially available, A antigen. WI-1 was purified by high-performance liquid chromatography over a DEAE-cellulose column. It eluted from the column at a point on the salt gradient corresponding to 460 to 490 mM NaCl, reflecting its acidic pI of approximately equal to 5.2. Purified WI-1 had a molecular mass of 120 kDa and contained a large amount of cysteine (85 residues) and aromatic amino acids but undetectable carbohydrate. In contrast, A antigen had a molecular mass of 135 kDa and contained 37% carbohydrate. Immunological comparison of the two antigens showed that, when radiolabeled, WI-1 was more reactive with anti-Blastomyces antisera than A antigen but did not cross-react with anti-Histoplasma antisera. Proteinase digestion of WI-1 eliminated its recognition by anti-WI-1 and anti-Blastomyces antisera. Proteinase treatment of A antigen had no effect on its recognition by anti-Blastomyces or anti-Histoplasma antisera, but periodate treatment abolished recognition by anti-Histoplasma antisera, indicating that the cross-reactive determinant(s) of A antigen is displayed on the accompanying carbohydrate. In further studies, anti-WI-1 antiserum reacted with A antigen and, conversely, anti-A antiserum and monoclonal antibodies (MAbs) reacted with WI-1, indicating a shared determinant on the two antigens. A recombinant 25-amino-acid repeat, recently cloned from WI-1 and found to be the major target of antibody recognition of WI-1, reacted strongly with anti-A antiserum and MAbs. In MAb competition tests, MAbs specific for the 25-residue repeat abolished binding of anti-A antiserum to A antigen. In antigen inhibition tests, the recombinant repeat abolished binding of anti-A antiserum to A antigen. These results demonstrate that the repeat is the major site of antibody recognition of both WI-1 and A antigen and that the recombinant, nonglycosylated peptide could replace either native antigen in formatting better diagnostic tests for blastomycosis. Moreover, they suggest that producing fungal protein antigens as nonglycosylated peptides in a procaryotic expression system may circumvent problems of antigen cross-reactivity that are due to posttranslational modification.
The autosomal recessive mutation mnd2 results in early onset motor neuron disease with rapidly progressive paralysis, severe muscle wasting, regression of thymus and spleen, and death before 40 days of age. mnd2 has been mapped to mouse chromosome 6 with the gene order: centromere-Tcrb-Ly-2-Sftp-3-D6Mit4-mnd2-D6Mit 6, D6Mit9-D6Rck132-Raf-1, D6Mit11-D6Mit12-D6Mit14, mnd2 is located within a conserved linkage group with homologs on human chromosome 2p12-p13. Spinal motor neurons of homozygous affected animals are swollen and stain weakly, and electromyography revealed spontaneous activity characteristic of muscle denervation. Myelin staining was normal throughout the neuraxis. The clinical observations are consistent with a primary abnormality of lower motor neuron function. This new animal model will be of value for identification of a genetic defect responsible for motor neuron disease and for evaluation of new therapies.
Crosses between heterozygous transgenic mice from line 5053 produced offspring with progressive irreversible hair loss beginning at day 19. With increasing age, the skin of these animals became thicker and plicated in appearance. Histological analysis revealed the complete absence of normal hair follicles and numerous intradermic cystic structures, which enlarged with time and became filled with keratinaceous material. Test crosses demonstrated that the affected animals are homozygous for the transgene insertion. The clinical and histological phenotype of the new mutant closely resembles that of the rhino allele at the hairless locus on Chromosome (Chr) 14. Complementation tests and linkage analysis indicate that the transgene has interrupted the hairless locus. It has been demonstrated previously that mutation at the hr locus is accompanied by a variety of immune deficiencies. Many of the older affected transgenic mice developed an impetigo-like skin eruption which responded to antibiotic ointment and which may reflect impaired immune function. The transgenic allele, hrTgN5053Mm, will be useful for identification of the transcription unit of the hairless locus.
This is a retrospective analysis of all patients with a raised titre of ANCA in a single centre over a two-year period. Sixty-five patients were identified and clinical data is presented for 58 of these-34 male and 24 female. The median age is 56 years (13-83). Fourteen patients had Wegener's granulomatosis, 14 microscopic polyarteritis nodosa and 30 had other diagnoses. The patients with unexpectedly positive results are discussed in detail. This study confirms the sensitivity of ANCA in Wegener's granulomatosis and microscopic polyarteritis nodosa but suggests that the test is not as specific as initially claimed.
Despite advances in maternal fetal medicine, the management of severe twin-to-twin transfusion syndrome in the second trimester presents a significant challenge. Presently, there is no uniformly accepted management protocol that is available for the treatment of this syndrome. We report the use of indomethacin in three cases of severe twin-to-twin transfusion syndrome in the second trimester. In the three cases of severe twin-to-twin transfusion syndrome no reduction of amniotic fluid in either sac was demonstrated. Two cases were complicated by single intrauterine fetal death within 72 hours of initiating indomethacin therapy. Because of our experience with these three cases, we conclude that indomethacin does not prevent perinatal mortality in patients with severe twin-to-twin transfusion syndrome.
Examination by electron microscopy of faeces from two separate cases of young cats with diarrhoea revealed the presence of 28 nm viral particles morphologically consistent with an astrovirus. No visible cytopathic effect was observed when the virus was inoculated into a feline kidney cell culture.
Different exocellular extracts were isolated by concentrating the supernatants of yeast- and mycelial-phase Candida albicans cultures incubated in a synthetic medium. The only difference between the extracts obtained from the two phases was the presence in those obtained from mycelial cultures of a polysaccharide-rich, high-molecular-mass component, migrating in SDS-polyacrylamide gels at a position that would correspond to proteins with molecular masses of 245-265 kDa. The electrophoretic band patterns obtained before and after concanavalin A-Sepharose 4B affinity column treatments confirmed that the 245-265 kDa band was the only one of mannoprotein nature. The extract obtained from 24 h mycelial-phase culture (EA) was selected as the exocellular antigen for this work. The dry weight of EA obtained from 1 litre of culture medium was 30 mg; it contained 53% carbohydrate (18.3% glucose and 21.7% mannose measured by gas-liquid chromatography) and 10% protein. Rabbit antisera against EA were absorbed with yeast-phase organisms and used to stain Western blots of gels loaded with EAs. These antisera clearly recognized bands in the 21, 33 and 44 kDa areas. The antiserum obtained was employed to develop a double-antibody enzyme-linked immunosorbent assay for measuring EA concentrations in a culture medium. Most of the EA was released during the exponential phase of growth.
A 120-kD glycoprotein antigen abundantly expressed on Blastomyces dermatitidis yeasts is a target of cellular and humoral immune responses in human infection. To investigate the antigen and immune response more carefully at the molecular level, we screened an expression library from B. dermatitidis to identify clones that encode this antigen, designated WI-1. A 942-bp cDNA was isolated by immunologic screening with polyclonal, rabbit anti-WI-1 antiserum. Northern hybridization analysis showed that the cDNA hybridized to yeast message approximately equal to 3.9 kb. DNA and deduced protein sequence analysis of the clone demonstrated a 25-amino acid repeat arrayed in tandem, present in 4.5 copies near the 5' end, and rich in predicted antigenic epitopes. Further analysis showed strong homology in these tandem repeats with invasin, an adhesin of Yersiniae. Cloned cDNA was used to express a 30-kD fusion protein strongly recognized in western blots by rabbit anti-WI-1 antiserum, and by sera from all 35 blastomycosis patients studied. The fusion protein product of subcloned cDNA encoding only the tandem repeat also was strongly recognized in western blots by sera from the 35 blastomycosis patients, but not by sera from 10 histoplasmosis and 5 coccidioidomycosis patients. An antigen-inhibition radioimmunoassay showed that the tandem repeat alone completely eliminated rabbit and human anti-WI-1 antibody binding to radiolabeled native WI-1. From these results, we conclude that the 25-amino acid repeat of WI-1 displays an immunodominant B cell epitope, and that the carboxyl-terminus of the molecule exhibits an architecture that may promote adhesion of Blastomyces yeasts to host cells or extracellular matrix proteins and ultimately provide a clearer picture of the molecular pathogenesis of blastomycosis.
This study focused on the belief of some nurse educators that caring cannot be taught directly and is learned by students from faculty role-modeling and faculty student interactions in clinical, classroom, and other situations. The purpose was to further explore these beliefs to determine if nursing students perceived that they learn caring behaviors through observing role-modeling by faculty, as well as to explore students' perceptions of other means by which they learn about caring. Since opportunities for faculty to model nurse caring behaviors in the clinical setting are varied and serendipitous, a videotaped scenario simulating a patient care situation, using professional actors, was created and shown to nursing students. The videotape was seen by 137 BSN and ADN students who then recorded their perceptions on a two-page open-ended questionnaire developed by the researchers. Results from this study indicated that students do learn about caring from faculty role-modeling, as well as from health care staff they encounter, often in a very paradoxical way. Many interesting and unintended results also occurred through the use of this research approach.
The cytotoxic effects of Taxol and/or ionizing radiation were evaluated in four human tumor cell lines. The recognized antimicrotubular effects of the drug leading to transitory accumulations of cells in the G2/M phase of the cell cycle, the most radiosensitive phase of the cycle, prompted this assessment of the potential for Taxol to function as a cell-cycle, phase-specific radiosensitizer. Taxol alone was cytotoxic to all four cell lines at low (< 25 nM) concentrations. A Taxol concentration of 10 nM for 24 hours led to 48, 15, 8, and 4.4% of cells retaining clonogenic potential for melanoma, two cervical carcinomas, and astrocytoma, respectively. There were significant Taxol concentration-time-dependent differences in response between the cell lines. Cell lines also showed significant differences in their responses to ionizing radiation. Combined treatment resulted in a demonstration of radiation sensitization with the astrocytoma and melanoma cell lines but not with the cervical carcinoma cell lines. Sensitizer enhancement ratios at the 10% cell survival level were 1.8 for 10 nM Taxol for 24 hours with the astrocytoma cells and 1.2 for 40 nM Taxol for 24 hours with the melanoma cells. The cervical carcinoma cell lines showed an additive effect for radiation and Taxol at all drug concentrations; that is, combined treatments elicit an additive or supra-additive response with, however, no simple relationship between Taxol concentration, Taxol time of treatment, and radiation dose in optimizing cytotoxic effectiveness. Combined modality treatments using relatively low concentrations of Taxol and ionizing radiation can result in an enhanced response and, at the least, an additive response, which could be advantageous in a clinical setting.
In order to determine whether acromegaly is still associated with increased mortality, a hospital case note review of all patients with acromegaly followed up in Stoke-on-Trent since 1967 was carried out. Of 79 subjects identified, 51 are alive and being monitored and 28 have died. Mortality was compared to the general population by life table analysis. Secretion of growth hormone was assessed and compared in dead and alive patients. The effect of diabetes, hypertension, and growth hormone secretion on long-term outcome was assessed. Acromegaly is still associated with increased mortality, with an overall ratio of observed to expected deaths equal to 2.68 (95% C.I. 1.8-3.9; p < 0.001), but the survival of 31 (39%) patients whose growth hormone level had been reduced to below 5 mU/l was equal to that of the general population (O/E = 1.42; 95% C.I. 0.46-3.31: p > 0.05). The dead patients had had significantly higher growth hormone levels than those still alive, but mortality did not appear to be influenced by diabetes or hypertension. The cause of death was vascular in 57% of cases. Growth hormone hypersecretion is still associated with excess mortality in acromegaly. The present study suggests that the therapeutic objective should be to lower average daytime growth hormone levels to less than 5 mU/l. There is need for a large study to compare different modes of treatment in terms of their effect on growth hormone secretion and on long-term outcome.
We issue a call for an "osteopathic medical renaissance" in teaching osteopathic principles and osteopathic manipulative techniques. This article describes a seminar series in the postdoctoral training program at the College of Osteopathic Medicine of the Pacific. We ask osteopathic physicians to enhance their manual dexterity skills to better serve as role models for physicians-in-training. We challenge osteopathic physicians to stimulate a renewed emphasis in teaching distinctive osteopathic medical care.
As a first step toward the elucidation of a simple animal model in which to investigate annexin function, we identified, isolated, and characterized a novel annexin from Hydra vulgaris, annexin XII. A hydra cDNA library was screened using a probe generated by polymerase chain reaction from primers based on the partial amino acid sequence of annexin XII. Annexin XII cDNA was cloned and the functional protein was expressed in high yields in Escherichia coli. The annexin XII cDNA sequence predicted a 316-amino acid protein that had between 44 and 54% sequence identity with the Ca2+-binding core domains of previously characterized vertebrate and Drosophila annexins. The amino-terminal domain of annexin XII did not have sequence similarity with other known annexins except at and around a site that resembled known protein kinase C (PKC) phosphorylation sites in other annexins. As anticipated from its sequence, annexin XII was a high affinity substrate for purified rat brain PKC; half-maximal phosphorylation occurred below 0.1 microM annexin XII, and incorporation of up to 0.8 mol of phosphate/mol of annexin XII was observed. A PKC-like activity in hydra extracts also phosphorylated annexin XII. In summary, hydra promises to be a valuable model system for investigating the biological function of annexins and for determining how this function is modulated by PKC phosphorylation.
Endothelins (ET) are potent vasoconstrictor peptides that also function as mitogens for numerous cell types. Although regulation of second messenger pathways by ET peptides has been extensively investigated, little is known about the pathways of nuclear signaling by which ET controls gene expression. The present experiments investigated whether fos and jun contribute to nuclear signaling and gene regulation by ET isopeptides. ET isopeptides induced a subset of fos and jun mRNAs in mesangial cells, including c-fos, fra-1, c-jun, and JunB. fos and jun mRNAs were induced as members of the immediate-early gene response. Activation of the high affinity ET receptor moderately increased c-fos and fra-1 mRNA, whereas activation of the low affinity receptor markedly induced both fos and jun mRNAs. Thus, different ET receptor subtypes evoke distinct patterns of fos and jun induction. Prominent isopeptide- and cell-specific differences in the magnitude and kinetics of fos and jun expression were observed. Most striking was the marked elevation of c-fos steady-state mRNA and protein by ET-1, as compared with ET-3. In addition, ET-1, but not ET-3, increased transcriptional activity conferred by an AP-1 cis-element and directed collagenase gene expression. These results suggest that differential regulation of fos and jun expression and of AP-1 cis-element activity by ET isopeptides contributes to regulation of gene expression by ET. Furthermore, a role for AP-1 in mitogenic signaling by ET is suggested by the close correlation between AP-1 cis-element activity and cell growth.