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Biomedical subjects

C Griffin

Publications and source records attributed to C Griffin.

At least 37 records · Page 2Linked to original sources
PubMed1999

Novel application of PhastSystem polyacrylamide gel electrophoresis using restriction fragment length polymorphism--internal transcribed spacer patterns of individuals for molecular identification of entomopathogenic nematodes.

différences! [editorial] [editorial]onomic way of identifying and assigning nematodes to taxons, which had already been determined either by comparative sequence analysis of nuclear rDNA internal transcribed spacer (ITS) region or by other methods of molecular or conventional taxonomy, is provided. Molecular identification of entomopathogenic nematodes (EPN) can be upgraded by basing it on PhastSystem polyacrylamide gel electrophoresis (PAGE) analysis of restriction fragment length polymorphism (RFLP) patterns of polymerase chain reaction (PCR)-amplified DNA derived from single nematodes of Steinernema or Heterorhabditis spp. Although analysis from single worms has previously been made on agarose gel, the resolution on PhastSystem PAGE gel is much higher. The DNA sequences selected for analysis were those constituting the internal transcribed spacer region between the 18S and 26S rDNA genes within the rRNA operon. RFLP analysis was carried out by gel electrophoresis on the PhastSystem (Pharmacia) as detailed elsewhere (Triga et al., Electrophoresis 1999, 20, 1272-1277. The downscaling from conventional agarose to PhastSystem gels resulted in pattern of DNA fragments differing from those obtained with agarose gel electrophoresis under conventional conditions by increasing the number of detected fragments. The approach supported previous species identifications and was able to identify several unclassified isolates, such as those from Hungary and Ireland, and provides a method for identification of previously unclassified strains. We confirmed that Heterorhabditis "Irish Type", represented by two strains of different geographical origin, comprise a species different from H. megidis. We also confirmed that strain IS5 belongs to the species H. indicus rather than to H. bacteriophora, as had been suggested previously.

Animals↗
PubMed1999

SZF1: a novel KRAB-zinc finger gene expressed in CD34+ stem/progenitor cells.

The identification and study of genes expressed in hematopoietic stem/progenitor cells should further our understanding of hematopoiesis. Transcription factors in particular are likely to play important roles in maintaining the set of genes that define the stem/progenitor cell. We report here the identification of a putative KRAB-zinc finger gene (SZF1) from a cDNA library prepared from human bone marrow CD34+ cells. Characterization of SZF1 implicates its role in hematopoiesis. The predicted protein contains a highly conserved KRAB domain at the NH2 terminus and four zinc fingers of the C2H2 type at the COOH terminus. Two alternatively spliced products of SZF1 were isolated, which predict proteins of 421 (SZF1-1) and 361 (SZF1-2) amino acids, differing from each other only at the carboxy terminus. The two transcripts of SZF1 have different expression patterns. SZF1-2 is ubiquitously expressed, as indicated by Northern blot, RNase protection, and reverse transcriptase polymerase chain reaction. SZF1-1 expression, in contrast, was detected only in CD34+ cells. We recently isolated the promoter region for the stem/progenitor cell expressed FLT3/FLK-2/STK-1 gene and used this region to generate a reporter construct to test the effect of SZF1 expression. Cotransfection of the reporter construct with SZF1 constructs showed that SZF1-2 repressed transcription three- to fourfold, whereas SZF1-1 showed a lower level of repression. The expression pattern of SZF1 transcripts and the transcriptional repression of a CD34+-specific promoter demonstrate a possible role for SZF1 in hematopoietic stem/progenitor cell differentiation.

Alternative Splicing↗
PubMed1999

Staphylococcal scalded skin syndrome in an adult associated with methicillin-resistant Staphylococcus aureus.

We report the first adult case of staphylococcal scalded skin syndrome (SSSS) due to methicillin-resistant Staphylococcus aureus (MRSA). This case is particularly unusual as the MRSA produced toxic shock syndrome toxin 1 and enterotoxin, but not exfoliatoxin. SSSS was originally described in neonates and is thought to result from exfoliatins which produce subcorneal splitting of the epidermis and are only produced by certain strains of S. aureus. This case reflects the range of toxins that can be associated with SSSS and the clinical manifestations of MRSA infection in adult patients.

Aged↗
PubMed1999

Lymphoproliferative disorder of fetal origin presenting as oligohydramnios.

Lymphoma involving the placenta or fetus remains a very rare event. All cases reported to date have shown the lymphoma cells to be of maternal origin in that the tumor cells have preferentially involved the intervillous spaces with sparing of the villi and fetal circulation. We report a novel case of a monoclonal primary placental Epstein-Barr virus (EBV)-associated B-cell lymphoma of fetal origin. The placenta of a 20-week stillborn fetus born to a 19-year-old gravida 1 para 0 woman, presenting with oligohydramnios, showed a large cell infiltrate confined within villi and sparing the intervillous spaces, indicative of preferential involvement of the fetal circulation. Necropsy did not show any other site of involvement by malignant lymphoma or other abnormalities. Immunophenotypic studies showed the tumor cells to be of B-cell phenotype with a relatively high proliferation rate. EBV EBER1 RNA was identified in more than 95% of tumor cells, and polymerase chain reaction studies showed EBV EBNA1 strain type A and wildtype EBV LMP1. Analysis of the immunoglobulin heavy chain by polymerase chain reaction showed a monoclonal B-cell population. In situ hybridization studies using a commercially available probe directed at repeated sequences on the human Y chromosome showed a single intense signal within trophoblastic epithelium and lymphoma cells, indicative of male origin. The mother remains in good health 11 months after delivery.

Diagnosis, Differential↗
PubMed1999

Quality of diagnostic services for cancer: a comparison of open access and conventional outpatient clinics.

OBJECTIVE AND STUDY DESIGN: To assess quality of a quick and early diagnosis route (QED) by determining effectiveness and cost-effectiveness of five clinics compared with three conventional outpatient clinics. Prospective economic evaluation. Six-month cohort of all referrals (November 1996-April 1997). SUBJECTS: All referrals for suspected cancers of: upper gastro-intestinal tract; urinary tract, prostate and testis; skin. EFFECTIVENESS: Median days saved between GP referral and date of: diagnostic appointment; consultant decision; intervention. RESULTS: GP referral to diagnostic appointment: QED was effective (median days) for all clinics. Diagnostic appointment to consultant decision: QED was effective for testicular and haematuria clinics. Consultant decision to intervention: QED was effective for haematuria, testicular and melanoma clinics. COST-EFFECTIVENESS: Extra (incremental) NHS cost per patient diagnosed. RESULTS: Less than 5 Pounds per day saved between GP referral and diagnostic appointment for: endoscopy; haematuria; prostate; testicular; melanoma. Less than 3 Pounds per day saved between GP referral and consultant decision for: testicular; haematuria. Less than 3 Pounds per day saved between GP referral and intervention for: endoscopy; haematuria; testicular; melanoma. CONCLUSION: A "quick and early" diagnostic route provides a higher quality service through improved effectiveness and cost-effectiveness compared to conventional outpatients.

Cohort Studies↗
PubMed1999

Two functionally different protein isoforms are produced from the chicken estrogen receptor-alpha gene.

The existence of two forms of the chicken estrogen receptor-alpha protein (ER-alpha) in chicken tissues is demonstrated: the previously reported receptor (cER-alpha form I), which has a size of 66 kDa, and a new form (cER-alpha form II), which lacks the N-terminal 41 amino acids present in form I and thus gives rise to a protein of 61 kDa. Whereas the 66-kDa protein is the translation product of several cER-alpha mRNAs (A1-D), the cER-alpha protein isoform II is encoded by a new cER-alpha mRNA (A2), which is transcribed in vivo from a specific promoter that is located in the region of the previously assigned translation start site of the cER-alpha gene. SI nuclease mapping analysis reveals that cER-alpha mRNA A2 is liver enriched. The resulting cER-alpha forms I and II differ in their ability to modulate estrogen target gene expression in a promoter- and cell type-specific manner. Whereas cER-alpha form I activates or represses in a strictly E2-dependent manner, the truncated form is characterized by a partial transactivating or repressing activity in the absence of its ligand. Comparison of the N-terminal coding regions of different vertebrate ER-alpha reveal a conservation of the translation start methionine of the protein ER-alpha form II in other oviparous species but not in mammals. The expression of two classes of ER-alpha transcripts encoding the two ER-alpha receptor forms in the liver of Xenopus laevis and rainbow trout is demonstrated. Therefore, the existence of two functionally different protein isoforms produced from the ER-alpha gene is probably a common and specific feature in oviparous species.

5' Untranslated Regions↗
PubMed1999

Building your own lifeboat: working-class male offenders talk about economic crime.

This study examines the ways in which a group of working-class men serving custodial sentences and probation orders for money-related crimes talk about criminal activity and the implications of this talk for their gender identity. Using a critical social-psychological approach, we carried out nine semi-structured group discussions in probation centres and one open prison and then analyzed the transcripts using a combination of grounded theory and discourse analytic methods. The men critiqued dominant constructions of crime and argued that their criminal activity was justified in two related ways. First, they drew on a discourse of male breadwinning to argue that they were expected to provide for their families. Second, they argued that those now suffering under the broken promises made by the State should not be expected to conform to its rules. For the majority of men, earning through crime was talked about as a last resort and the parameters of 'what they did to whom' were informed by a Robin Hood-type cultural narrative. Finally, the study contextualizes and critically explores these patterns of discourse and their rhetorical use from a historical and structural perspective.

Adult↗
PubMed1998

CD34+ stem cell augmentation of elutriated allogeneic bone marrow grafts: results of a phase II clinical trial of engraftment and graft-versus-host disease prophylaxis in high-risk hematologic malignancies.

Although T cell depletion of allografts used in BMT has reduced GVHD, it has been associated with inferior engraftment and an increased risk of relapse. We have found that T cell depletion by counterflow centrifugal elutriation (CCE) also results in depletion of CD34+ stem cells. In order to determine if the discarded CD34+ cells would improve engraftment, we undertook a phase II trial of allogeneic BMT in which 110 patients (median age 43) with a variety of hematologic malignancies received CD34+ stem cell augmented, elutriated marrow grafts. The T cell-depleted grafts were tightly controlled and contained a mean of 4.3 x 10(7) mononuclear cells/kg, 3.3 x 10(6) CD34+ cells/kg, 1.5 x 10(5) CFU-GM/kg and 5.5 x 10(5) CD3+ T cells/kg. Median time to engraftment of granulocytes (>500/microl) was 16 days and of platelets (>50000/microl) was 25 days, comparable to that seen with unmanipulated marrow. No mixed hematopoietic chimerism was observed that was not associated with disease relapse. The four patients (3.6%) who failed to engraft were all at high risk because of prior donor transfusions or underlying marrow disorders. The incidence of GVHD was dependent on the duration of cyclosporin A (CsA) immunosuppression. In patients who received CsA for > or = 80 days, the incidence of clinically significant acute GVHD (>stage 1) and extensive, chronic GVHD was 5% and 11%, respectively. Peritransplant (< or = 100 day post-BMT) mortality for this group of patients was 15%. Event-free survival in selected subsets of patients compared favorably to previous studies in which patients received unmanipulated marrow allografts.

Adolescent↗
PubMed1998

Identification of novel chicken estrogen receptor-alpha messenger ribonucleic acid isoforms generated by alternative splicing and promoter usage.

Using the rapid amplification of complementary DNA ends (RACE) methodology we have identified three new chicken estrogen receptor-alpha (cER alpha) messenger RNA (mRNA) variants in addition to the previously described form (isoform A). Whereas one of the new variants (isoform B) presents a 5'-extremity contiguous to the 5'-end of isoform A, the two other forms (isoforms C and D) are generated by alternative splicing of upstream exons (C and D) to a common site situated 70 nucleotides upstream of the translation start site in the previously assigned exon 1 (A). The 3'-end of exon 1C has been located at position -1334 upstream of the transcription start site of the A isoform (+1). Whereas the genomic location of exon 1D is unknown, 700 bp 5' to this exon were isolated by genomic walking, and their sequence was determined. The transcription start sites of the cER alpha mRNA isoforms were defined. In transfection experiments, the regions immediately upstream of the A-D cER alpha mRNA isoforms were shown to possess cell-specific promoter activities. Three of these promoters were down-regulated in the presence of estradiol and ER alpha protein. It is concluded, therefore, that the expression of the four different cER alpha mRNA isoforms is under the control of four different promoters. Finally, RT-PCR, S1 nuclease mapping, and primer extension analysis of these different cER alpha mRNA isoforms revealed a differential pattern of expression of the cER alpha gene in chicken tissues. Together, the results suggest that alternative 5'-splicing and promoter usage may be mechanisms used to modulate the levels of expression of the chicken ER alpha gene in a tissue-specific and/or developmental stage-specific manner.

Alternative Splicing↗
PubMed1998

Differentially expressed messenger RNA isoforms of the human estrogen receptor-alpha gene are generated by alternative splicing and promoter usage.

The isolation and characterization of several new human estrogen receptor-alpha (hERalpha) mRNAs are described. Together with those previously identified, they give rise to a total of six hERalpha mRNA isoforms (A-F hERalpha mRNAs). Produced from a single hERalpha gene by multiple promoter usage, all these transcripts encode a common protein but differ in their 5'-untranslated region as a consequence of alternative splicing of five upstream exons (1B-1F). RT-PCR and S1 nuclease mapping analysis of these different hERalpha mRNA isoforms revealed a differential pattern of expression of the hERalpha gene in human tissues and cell types. The A hERalpha mRNA is the main isoform detected in mammary glands or in the tumor cell lines derived from this tissue. In endometrium, the predominant forms are the A and C hERalpha mRNA isoforms, whereas the C and F hERalpha mRNA isoforms are the major forms detected in ovary. Finally, high levels of the E hERalpha mRNA isoform are restricted to the liver with an increased expression in females. Taken together, our results demonstrate that the hERalpha gene is a complex genomic unit exhibiting alternative splicing and promoter usage in a tissue-specific manner.

Adolescent↗
PubMed1998

A phase II "window" study of topotecan in untreated patients with high risk adult acute lymphoblastic leukemia.

To further evaluate the activity of topotecan (TPT) in acute leukemia, TPT was administered (2.1 mg/m2/day for 5 days by continuous i.v. infusion) to adult patients with previously untreated acute lymphoblastic leukemia (ALL) with high-risk features (13 patients) or relapsed ALL (1 patient). Patients achieving a partial response or significant hematological improvement received a second course. All patients subsequently received standard treatment for ALL. Because complete response was achieved in only 1 of 14 patients, the study was terminated prematurely. An additional patient achieved minimal response, and a third patient normalized her hemogram despite ongoing leukemia in the marrow. Overall, six patients had significant hematological improvement (normalization of platelet and/or absolute neutrophil count). Two patients expired due to infections during induction chemotherapy. The primary nonhematological toxicities were mucositis and diarrhea. Exposure to TPT did not appear to influence the response to subsequent standard chemotherapy. The mean steady-state TPT plasma concentration, 16.1+/-1 nM, overlapped the range of LD90 values of primary human leukemia specimens. Cellular topo I content varied over a 3-fold range, encompassing levels found previously in relapsed patients. No relationship was found between topo I expression and markers of cellular proliferation or response to therapy. In contrast, low expression of the apoptosis inhibitor Bcl-2 was associated with response to TPT therapy. TPT has significant, albeit modest, single-agent activity against high-risk adult ALL. This study demonstrates the feasibility of evaluating promising new therapeutic agents in untreated patients with acute leukemia at high risk for failure with conventional therapy.

Adult↗
PubMed1996

Therapeutic expectations of patients with multiple sclerosis upon initiating interferon beta-1b: relationship to adherence to treatment.

This study, conducted in three separate outpatient health care delivery settings, examined the therapeutic expectations of patients with multiple sclerosis (MS) before they initiated interferon beta-1b therapy, the results of current educational procedures to correct unrealistic expectations, and the relationship between post-education expectations and discontinuing therapy. Ninety-nine consecutive patients were seen in a university based outpatient MS clinic, an academic group practice outpatient MS clinic, or a health maintenance organization outpatient neurology clinic. Before the educational sessions, 57% of the patients expressed unrealistically optimistic expectations regarding reduction in attack rate and 34% expressed unrealistically optimistic expectations regarding improvement in functional status. Educational procedures significantly altered unrealistic expectations but the results were sub-optimal since 33% of the patients maintained overly optimistic expectations regarding reduction in attack rate. Post-education unrealistic expectations of improvement in functional status were significantly related to discontinuing therapy within 6 months. Three adverse effects of therapy also were related independently to adherence to treatment: depression and flu-like symptoms were related to discontinuing therapy while soreness at injection site was related to continuing therapy.

Adjuvants, Immunologic↗
PubMed1995

Molecular cloning and chromosomal localization of the human homologue of a B-lymphocyte specific protein tyrosine kinase (blk).

A cDNA encoding the human homologue of the murine protein tyrosine kinase, blk, has been cloned from a human B-lymphocyte cDNA library by cross-species hybridization using the murine blk cDNA as a probe. The sequence of the 2608 bp human blk cDNA clone contains an open reading frame encoding a predicted 505 amino acid protein with SH3, SH2 and catalytic domains that contain consensus sequences of the src protein tyrosine kinase family. Comparison of human and murine blk sequences indicated that they share 86% amino acid identity, the most conserved region being the catalytic domain (93% identity). Like the murine blk gene human blk is expressed only in B lymphocytes. The human blk gene was mapped to chromosome 8 at p22-23.

Amino Acid Sequence↗
PubMed1995

A longitudinal study of granulocyte colony-stimulating factor levels and neutrophil counts in newborn infants.

PURPOSE: The goal of this study was to longitudinally measure endogenous granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) levels in newborn infants and to attempt to correlate these levels with neutrophil counts. PATIENTS AND METHODS: Samples for complete blood count, G-CSF, and GM-CSF were obtained from groups of healthy full-term infants at 0 (cord blood or nursery admission), 12, 24, 48, and 72 h. Samples were also obtained from premature infants at the above times and at 1 week. G-CSF and GM-CSF levels were measured using bioassays. RESULTS: Levels of G-CSF ranged from < 5 to 53,800 pg/ml. Levels were significantly higher (p < 0.001) in premature infants and decreased over time in all infants. White blood cell counts also decreased over the first week of life. All GM-CSF levels were below the detectable range. CONCLUSIONS: Levels of G-CSF at birth are higher than those seen in adults. These increased levels may partially explain the leukocytosis seen in the first week of life. This, as has been shown in preliminary studies, suggests that infants are capable of an increase in neutrophil count after administration of exogenous G-CSF.

Cell Cycle↗
PubMed1995

A rare cause of an acute abdomen in late pregnancy.

A case is presented where spontaneous rupture of a uterine arteriovenous malformation into the peritoneal cavity presented as an acute abdomen with fetal distress in late pregnancy. This is thought to be the first reported case of its type.

Abdomen, Acute↗