Search PubMed⌕ Search

Biomedical subjects

C Mason

Publications and source records attributed to C Mason.

At least 109 records · Page 6Linked to original sources
PubMed1991

Epstein-Barr virus infection acquired from a cadaveric renal transplant.

A 42-year-old man, seronegative for Epstein-Barr virus (EBV), received a cadaveric renal transplant. Serology from the 27-year-old male donor indicated an active EBV infection. Following treatment for acute rejection with OKT3 the recipient developed a severe systemic illness. Clinical features strongly suggested an acute EBV infection and serology showed seroconversion for EBV. The patient died and autopsy histology revealed widespread polymorphic lymphocyte infiltration in lymph nodes and solid organs. To our knowledge this is the first report of a kidney being transplanted from a donor who was subsequently shown to have had EBV infection at the time of organ retrieval. The EBV status of an organ donor should be considered more frequently.

Adult↗
PubMed1991

Project 2000: a critical review.

Project 2000 forms an example of nurses bringing about change proactively to make nurse education appropriate to the social, technological and medical advances of the second part of the twentieth century. Unexpected problems, however, are emerging as Project 2000 is implemented. It is argued in this article that these problems arise from a failure on the part of the United Kingdom Central Council in 1983 to anticipate the enormous changes that the health service is currently undergoing and a failure, therefore, to make connections between these changes and the educational and organisational changes involved in the implementation of Project 2000.

Education, Nursing↗
PubMed1990

Women as mothers in northern Ireland and Jamaica: a critique of the transcultural nursing movement.

Participant observation and structured interviews with selected groups of mothers in Northern Ireland and Jamaica revealed a variety of individual experiences that highlighted contrasts between the two cultures, and differences within each culture. The findings are used to illustrate the danger of cultural stereotyping, and the implications for the transcultural nursing movement are discussed.

Adolescent↗
PubMed1990

Analysis of the fowlpox virus genome region corresponding to the vaccinia virus D6 to A1 region: location of, and variation in, non-essential genes in poxviruses.

The DNA sequence of the fowlpox virus genome corresponding to the vaccinia virus D6 to A1 region has been determined. Translation of this sequence reveals fowlpoxvirus gene homologues corresponding to the D6, D7, D9, D10, D11, D12, D13 and A1 genes of vaccinia virus. In contrast, no gene homologue for the non-essential vaccinia virus D8 gene was present in fowlpox virus. Instead, a gene transcribed from the opposite strand to the vaccinia virus D8 gene showing no homology to any previously sequenced poxvirus gene was present. The amino terminus of the fowlpox virus D9 homologue had undergone substantial changes, including frameshifts which would be predicted to inactivate the gene. Insertion of a gene cartridge composed of the vaccinia virus p7.5 promoter and the lacZ gene into the fowlpox virus D8, D9 and D10 genes in vitro, followed by recombination into fowlpox virus, was carried out. Stable insertion mutants with the correct genotype were obtained for D8 and D9 which, when tested in chickens did not appear to have been attenuated. No stable insertion mutants were obtained for D10, indicating that this gene probably encodes a function which is essential for virus replication. The D8 and D9 genes of fowlpox virus represent useful insertion sites for the construction of recombinant fowlpox virus vaccines.

Amino Acid Sequence↗
PubMed1990

A 39,000 Mr immunodominant protein of fowlpox virus contains multiple copies of a 12 amino acid repeat sequence.

The nucleotide sequence of an unusual fowlpox virus gene which maps immediately upstream from the fowlpox virus 4b gene has been determined. The 34,000 Mr protein predicted to be encoded by the gene contains 11 copies of a 12 amino acid serine-rich repeat sequence. The seven amino-terminal copies of the repeat sequence are perfectly conserved but variation exists in the four carboxy-terminal copies. Three peptides were synthesized which contained either one copy of the repeat sequence, two copies of the repeat sequence or a hydrophilic amino-terminal region of the protein. All three peptides when injected with adjuvant into rabbits gave rise to antibodies which reacted strongly on Western blots of purified fowlpox virus proteins with a 39,000 Mr protein. When directly compared in Western blots the antipeptide sera were shown to recognize a protein comigrating with one of the two immunodominant proteins recognized by chicken anti-fowlpox virus sera taken 2 weeks post-infection. The virion protein is removed by treatment with sodium deoxycholate suggesting that it is located at or near the surface of the virus.

Amino Acid Sequence↗
PubMed1990

Allogeneic bone marrow transplantation in a program of intensive sequential chemotherapy for children and young adults with acute nonlymphocytic leukemia in first remission.

Eighty-seven consecutive children and young adults with acute nonlymphocytic leukemia (ANLL) were treated uniformly with induction chemotherapy based on daunorubicin and cytarabine (ara-C), with the addition of etoposide (VP-16) and azacytidine (5-Az) for refractory patients. Of the 65 patients who entered complete remission, 42 were eligible for assessment of response to intensive chemotherapy consisting of four pairs of drugs administered in sequential fashion. Nineteen others with available histocompatibility locus antigen (HLA)-compatible donors were assigned to receive allogeneic bone marrow transplants within 16 weeks from their dates of complete remission. Durations of continuous complete remission (CCR) in the two groups were not significantly different at a median follow-up time of 6 years (P = .30 by log-rank analysis). Kaplan-Meier estimates of CCR probabilities (+/- SE) at 6 years were 43% +/- 13% (transplantation) and 31% +/- 7% (sequential chemotherapy). Postremission failures in the sequential chemotherapy group resulted from bone marrow relapse in 23 of 29 patients (79%), whereas in the transplantation group, failures were equally divided between marrow relapse and transplantation-related complications of graft-versus-host disease (GVHD) or infection due to the immunosuppressive effects of ablative chemotherapy. Comparison of hematologic remission curves indicated a significant advantage for marrow transplantation in terms of systemic leukemia control (P = .06). Thus, in programs of intensive chemotherapy of the type described here, allogeneic marrow transplantation should be seriously considered as alternative therapy for patients in first remission who have an HLA-matched sibling donor, provided that effective methods for control of transplant-related complications are available.

Adolescent↗
PubMed1989

Human lymphocyte proliferative response to a sporozoite T cell epitope correlates with resistance to falciparum malaria.

To identify vaccine relevant T cell epitopes on the circumsporozoite (CS) protein of Plasmodium falciparum, the lymphocyte proliferative responses to 10 CS protein derived peptides were studied in 28 adult Kenyans, and correlated with resistance to malaria. Eight peptides, six of which were not overlapping, induced proliferation of lymphocytes from one to five volunteers, suggesting either genetic restriction of response to each of the T epitopes, or dominance of some T sites on the immunizing sporozoites. The 28 volunteers were radically cured of malaria and during the next 126 days 25 of the 28 were reinfected. Resistance to malaria was not correlated with antibodies to malaria Ag, but was significantly correlated with lymphocyte responses to CS protein residues 361-380 and 371-390. Among the 25 volunteers who became re-infected with malaria, lymphocytes from only two responded to a peptide including residues 361-380 of the P. falciparum CS protein, and only one to peptide 371-390. In contrast, lymphocytes from all three volunteers who did not become infected responded to peptide 361-380 (p = 0.003), and lymphocytes from two of the three responded to peptide 371-390 (p = 0.023). The significant correlation between proliferation to peptides 361-380 and 371-390 and resistance to malaria suggests that at least one epitope within these overlapping peptides is involved in a protective cellular immune response. The data support inclusion of these residues in future CS protein vaccines.

Adult↗
PubMed1989

Effective reinduction therapy for childhood acute nonlymphoid leukemia using simultaneous continuous infusions of teniposide and amsacrine.

The combination of teniposide (VM-26) and amsacrine (AMSA) was evaluated in a dose-finding and efficacy study in 58 patients with relapsed or refractory acute leukemia. Both agents were given as simultaneous continuous infusions for 72 h through separate i.v. lines. All patients were evaluable for toxicity and 57 were evaluable for response; only 2 of 20 with acute lymphoblastic leukemia (ALL), acute mixed-lineage leukemia, or chronic myelogenous leukemia in blast crisis achieved a complete remission (CR). More encouraging was a second-remission rate of 43% (13 complete and 3 partial) in the 37 patients with acute nonlymphoid leukemia (ANLL). Responses occurred only in patients who received VM-26 doses of greater than or equal to 200 mg/m2 per day and AMSA doses of greater than or equal to 100 mg/m2 per day. Thus, the CR rate for relapsed ANLL patients who received the higher doses of both agents was 40% (13 of 33). All responders had previously received epipodophyllotoxin therapy and 40% had also received AMSA. All but one patient had severe leukopenia (less than 2.0 x 10(9) leukocytes/l) and thrombocytopenia (less than 50.0 x 10(9) platelets/l) as a results of therapy. Severe mucositis (grade 3 or 4) was the dose-limiting toxicity. Our results indicate that VM-26 plus AMSA, given by continuous infusion, is effective in the treatment of ANLL. Further phase II studies should consider using VM-26 at 200 mg/m2 per day and AMSA at 100 mg/m2 per day, but the best administration schedule remains unclear.

Adolescent↗
PubMed1989

Hereditary white sponge naevus.

The authors report two cases of white sponge naevus in the same family, where the condition had clearly been inherited by the daughter from her mother. The positive family history aided correct diagnosis of this entirely benign lesion.

Adult↗
PubMed1988

Early intensification of chemotherapy for childhood acute nonlymphoblastic leukemia: improved remission induction with a five-drug regimen including etoposide.

We tested the value of early intensification of chemotherapy in 68 consecutive children with acute nonlymphocytic leukemia (ANLL) who were admitted to St. Jude Children's Research Hospital from November 1983 through March 1987. Fifty-eight patients (85%) entered complete remission after treatment with etoposide (VP-16)/cytarabine (ara-C) (A), followed by daunorubicin (Dauno)/ara-C/thioguanine (6-TG) (B) and then VP-16/azacytidine (5-AZ) (C). Thirty percent of the complete responders, mainly those with an M4 or M5 leukemia subtype, attained M1 marrow status after component A, 60% after A + B, and 10% after A + B + C. Induction failures resulted primarily from absolute or relative drug resistance; there was only one death during this phase of therapy. Postremission treatment consisted of three pairs of drugs (vincristine [VCR]/amsacrine [m-AMSA], or doxorubicin [Doxo]/6-TG/ara-C, and VP-16/cyclophosphamide [CTX]) administered sequentially in 6-week cycles for 22 months. Despite the high rate of remission induction, only 33% +/- 7% SE of the patients are expected to be failure-free survivors at 2 years. Remission durations were not significantly affected by the majority of factors examined in this study, with the exception of marrow cellularity after VP-16/ara-C induction therapy. Patients with less than or equal to 5% leukemic cells survived relapse-free for a median of 36.1 months, compared with 11.3 months for the group with a larger infiltrate (P = .01). Although postremission therapy did not improve the percentage of long-term failure-free survivors, the induction regimen we used appears highly effective, and its components should be considered for inclusion in other treatment programs.

Acute Disease↗
PubMed1987

[Local immune reaction in human intestinal spirochetosis].

The pathogenetic and clinical importance of intestinal spirochaetes in man is still unresolved. In 12 patients mainly presenting with mild diarrhoea, light and electron microscopy demonstrated massive spirochaetal infestation of the colonic mucosa (spirochaetosis). There were several hitherto unreported features: spirochaetes adhered not only to the surface epithelium of the intestine but were also present within epithelial cells and subepithelial macrophages; many partially degranulated mast cells were noted within the epithelium; there was a marked increase of IgE plasma cells within the lamina propria. In control biopsies intraepithelial mast cells were absent and IgE cells occurred only sporadically. Penetration of the microorganisms into the intestinal mucosa may be responsible for this unusual immune response. Spirochaetes, symptoms and findings disappeared after antibiotic therapy. The authors therefore suggest that intestinal spirochaetosis can cause clinical symptoms in man, and that spirochaetes should not invariably be considered harmless commensals.

Colonic Diseases↗
PubMed1987

Spirochaetosis of the human rectum associated with an intraepithelial mast cell and IgE plasma cell response.

In two patients presenting with mild intestinal symptoms, rectal spirochaetosis was the only morphological abnormality diagnosed by light microscopy. A re-evaluation of the morphological changes using electron microscopy and immunohistochemistry showed certain unusual features: the microorganisms were observed within epithelial cells and in subepithelial macrophages; there were numerous partially degranulated intraepithelial mast cells; and there was a marked increase in the proportion of IgE plasma cells within the lamina propria. Mucosal penetration by the organisms may be responsible for the unusual immune response. In one patient, treatment with antibiotics eliminated the spirochaetes and resulted in a clinical improvement. Spirochaetes should not always be considered as harmless commensals in the colon.

Adult↗
PubMed1987

Growth cone morphology varies with position in the developing mouse visual pathway from retina to first targets.

We have labeled the growth cones of retinal ganglion cell axons with HRP in intact mouse embryos. This has allowed us to visualize growth cone morphology during outgrowth along an entire CNS pathway from origin to target; to ask whether growth cone forms, and thus behaviors, differ at various points along the pathway; and to study the relationships of growth cones with the cellular environment. During the major period of axon outgrowth between embryonic day (E) 12 and 15, growth cones in the optic nerve are highly elongated (up to 40 microns) and have lamellopodial expansions, but the majority lack the microspikes or filopodia characteristic of many growth cones. Within the optic chiasm (E13-15), most growth cones shorten and spread, and project several short filopodia. In the optic tract, growth cones become more slender and again lack filopodia, resembling sleeker versions of optic nerve growth cones. Near the first target region (lateral geniculate nucleus), growth cones with filopodia arise from individual axon lengths and turn medially toward the target. Within target regions, the branches of immature axon arbors are tipped by minute swellings rather than by the enlarged growth cones prevalent during outgrowth toward targets. Electron-microscopic analysis of identified labeled growth cones in the optic nerve reveal intimate interactions between growth cones and glia or other growth cones in the form of invaginating contacts. In the optic nerve, growth cones contact immature glial (neuroepithelial) cells somewhere along their length, and also envelop bundles of neurites. In the chiasm, single growth cones simultaneously relate to many different profiles. These results demonstrate that in this single pathway from origin to targets, growth cone morphology varies systematically with position along the visual pathway. During outgrowth, simple growth cones are prominent when axons follow well-defined common pathways, and more elaborate filopodial forms appear when growth cones diverge, as they turn or come to decision regions. Together with observations in vitro and in nonmammalian nervous systems in situ, these data serve as reference points for testing to what extent growth cone form reflects intrinsic factors and interactions with the environment.

Animals↗