Peripheral anchorage of dermal equivalents

Human fibroblasts can induce collagen gel contraction with different kinetics depending on the number of cells and on the collagen concentration within this lattice, which has been considered as a dermal equivalent. Skin equivalent is a combined culture of dermo-epidermal layers which may be of therapeutic value in the treatment of burn patients. However, the current production of the dermal equivalent component gives results that present many drawbacks for their eventual clinical use as a first step in obtaining a skin equivalent. These include: (i) final surfaces which are very small; less than 20% of the initial size (ii) excessive thickness which may hamper successful graft take (iii) fibroblasts that do not have an arrangement comparable with normal dermal tissue. We propose, as a solution to these problems, the utilization of a 5-mm-wide fibre-glass filter ring peripherally attached to the surface of the Petri dishes to prevent inordinate contraction while the fibroblasts reorganize the collagen gel. Using this technique the initial surface was preserved and the dermal equivalent contracted only in thickness. Histological analysis of these anchored equivalents confirmed an alignment of fibroblasts and collagen fibres resembling normal dermal tissue. We consider this method useful in the development of dermo-epidermal sheets for clinical purposes.     

EPSTEIN–BARR VIRUS (EBV) INFECTION IN INFECTIOUS MONONUCLEOSIS: VIRUS LATENCY,REPLICATION AND PHENOTYPE OF EBV-INFECTED CELLS

Primary Epstein–Barr virus (EBV) infection may manifest itself as a benign lymphoproliferative disorder, infectious mononucleosis (IM). EBV infection has been characterized in lymphoreticular tissues from nine patients with IM using the abundantly expressed EBV-encoded nuclear RNAs (EBERs) as a marker of latent infection. Expression of the virus-encoded nuclear antigen (EBNA) 2 and of the latent membrane protein (LMP) 1 was seen in variable proportions of cells in all cases. Double labelling revealed heterogeneous expression patterns of these proteins. Thus, in addition to cells revealing phenotypes consistent with latencies I (EBNA2⁻/LMP1⁻) and III (EBNA2⁺/LMP1⁺), cells displaying a latency II pattern (EBNA2⁻/LMP1⁺) were observed. Cells expressing EBNA2 but not LMP1 were also detected; whilst this may represent a transitory phenomenon, the exact significance of this observation is at present uncertain. EBER-specific in situ hybridization in conjunction with immunohistochemistry revealed expression of the EBERs mainly in B-lymphocytes, many of which showed features of plasma cell differentiation. By contrast, convincing evidence of latent EBV infection was not found in T-cells, epithelial or endothelial cells. Double-labelling immunohistochemistry revealed expression of the replication-associated BZLF1 protein in small lymphoid cells, often showing plasmacytoid differentiation. There was no unambiguous expression of this protein in other cell types. These results suggest that B-cells are the primary target of EBV infection and that plasma cells may be a source of infectious virus found in the saliva of IM patients. © 1997 John Wiley & Sons, Ltd.     

Wheat Starch Intolerance in Patients With Celiac Disease

Objective Evaluate in patients with celiac disease the tolerance of prolonged consumption of small amounts of gliadin contained in products containing wheat starch. Design Open 1-year trial of the addition of wheat starch to a gluten-free diet in a cohort of adult patients with biopsy-proven celiac disease who had never consumed wheat starch. The control group consisted of patients with celiac disease who tolerated wheat starch.Subjects Seventeen patients with celiac disease and 14 control patients, all diagnosed according to criteria of the European Society of Pediatric Gastroenterology and Nutrition, were recruited from the Canadian Celiac Association and the Quebec Celiac Foundation.Setting The study was conducted in the outpatient clinic of the Gastroenterology and Nutrition Service of Ste Justine Hospital, Montreal, Quebec, Canada. Interventions Patients were asked to consume four to six portions daily of a wheat starch-containing product, mainly bread, for up to 1 year.Main outcome measures The gliadin content of the wheat starch product used in this trial was quantified by enzyme linked irnmunosorbent assay. Patient outcome measures included symptoms, nutritional parameters (anthropometric data, complete blood count, serum folate and iron levels), and immunologic parameters (antigliadin antibody and antiendomysium antibody titers).Results A quantifiable amount of immunoreactive gliadin (0.75 mg/100 g) was found in the wheat starch. The majority of the patients with celiac disease (11 of 17) who had never consumed wheat starch previously developed symptoms, which resolved within weeks of discontinuing the product. Relapse of skin lesions was seen in two of three patients with coexisting dermatitis herpetiformis. No weight loss or biochemical changes were observed. Despite the presence of symptoms, antigliadin antibody and antiendomysium antibody determinations were not useful to detect the clinical intolerance.Applications The innocuousness of the long-term ingestion of “gluten-free” products containing wheat starch is still unproven, and prolonged use of such products by patients with celiac disease cannot be recommended.     

CD5 — T lymphocytes in renal transplant recipients

Summary The CD3 + CD5— subpopulation of T cells has been shown to be increased in patients following allogeneic bone marrow transplantation, and a statistical association has been found with graft-versus-host disease (GVHD). We studied this population in renal transplant recipients. There was no correlation with rejection episodes but we found an increase in this CD3 + CD5 — population in patients on cyclosporin, and we suggest that these cells may be involved in the mechanism of action of this drug. In patients on azathioprine the absolute number of CD3 + CD5 — lymphocytes is reduced, along with other lymphoid subpopulations.     

Synthesis and biological activity of dynorphin-(1 - 13) and analogs substituted in positions 8 and 10

Dynorphin-(1–13) (Dyn-(1–13)) and various analogs substituted in positions 8 and 10 were synthesized by the solid-phase technique and analyzed for their ability to inhibit the electrically evoked contraction of the guinea pig ileum (GPI) and to compete with the binding of [³H]-ethylketocyclazocine (EKC, k ligand), [³H]-[D-Ala², MePhe⁴-Gly-ol⁵]-enkephalin (DAGO, μ ligand) and [³H]-[D-Ser², Thr⁶]-Leu-enkephalin (DSLET, δ ligand) to membrane preparations of the guinea pig cerebellum or rat brain. Introduction of Ala in position 8 decreased the activity of the peptide on the GPI by 50% but induced a 2.22-fold increase in its affinity for the k receptor ([³H]-EKC binding displacement from guinea pig cerebellum; Ki of 0.05 nM as compared with 0.11 nM for Dyn-(1–13)). On the other hand, the ability of [Ala⁸]-Dyn-(1–13) to displace the binding of [³H]-DSLET from rat brain membranes was decreased by a factor of 1.7 while its affinity for the μ receptor was not greatly affected ([³H]-DAGO displacement; Ki of 0.44nM as compared with 0.50nM for Dyn-(1–13)). Replacement of position 8 by D-Ala caused similar changes in the activity of the peptide but the increase in its affinity for the k site was somewhat smaller (Ki of 0.08 nM as compared with 0.11 nM). [D-Pro¹⁰]-Dyn-(1–13) was equipotent to [Ala⁸]-Dyn-(1–13) in the GPI but its affinity for the μ binding site was decreased by a factor of 2.7 as compared with Dyn-(1–13). The affinity of [D-Pro¹⁰]-Dyn-(1–13) for the other binding sites (k and δ) was not greatly affected. Replacement of positions 8 or 10 by Trp or D-Trp decreased the activity on the GPI by more than 50% as well as the affinity for most receptor types. These data indicate that the selectivity of Dyn(1–13) for the k opioid receptor can be increased either by increasing its affinity for the K binding site ([Ala⁸]-Dyn-(1–13)) or lowering its potency for other binding sites, [Ala⁸]-Dyn-(1–13) being less potent on δ sites and [D-Pro¹⁰]-Dyn-(1–13) less potent on μ sites.     

Acute Myelogenous Leukaemia Following Cytotoxic Therapy: Five Cases and Review

Acute myelogenous leukaemia (AML) following cytotoxic chemotherapyhas been reported increasingly. Five new cases are presentedincluding the first described following treatment for immunethrombocytopaenia. A review of the literature has revealed 226case reports of treatment-linked AML with sufficient detailto permit further study. Of the total of 231 patients, 76(33per cent) followed Hodgkln's disease, 59(25.5 per cent) multiplemyeloma, 22 (9.5 per cent) non Hodgkin's lymphoma, 32 (14 percent) other solid tumours and 42 (18 per cent) non-malignantdiseases. The time interval from the start of chemotherapy tothe diagnosis of AML was similar in all disease groups whetherthe patients had received radiotherapy or not Differences emergedwhen the duration of exposure to chemotherapy was analysed inthe individual disease groups; exposure was shorter in thosepatients treated for Hodgkin's disease and solid tumours thanwith the others suggesting that the pattern of administrationof chemotherapy may be important The effects of radiotherapyin addition to chemotherapy could not be defined precisely,but the study highlights the particular risk that appears toarise from alkylating agents, and the need to define optimalmethods of administration of chemotherapy with minimal riskof inducing leukaemia. Present address: Royal South Hampshire Hospital, Southampton.     

The Australian experience of nurses' preparedness for evidence-based practice

Aim  This study aimed to determine current knowledge and attitudes towards evidence-based practice (EBP) among pre- and post-registration nurses in New South Wales (NSW), Australia.
Background  Educational and clinical strategies for EBP in nursing assume a readiness to interpret and integrate evidence into clinical care despite continued reports of low levels of understanding and skill in this area.
Method  Perceptions of EBP were examined through a self-complete, anonymous postal survey distributed to 677 (post-registration) clinical nurses and to 1134 final year (pre-registration) nursing students during 2002 and 2003.
Results  A completed survey was returned by 126 post-registration and 257 final year nursing students (combined 21% response rate). Both pre- and post-registration nurses had a welcoming attitude towards EBP. Pre-registration nurses expressed more confidence in their EBP skills but self-rated knowledge and skill were low to moderate in both groups.
Conclusion  Nurses in Australia are clearly supportive of EBP but it is incorrect to assume that even recent graduates have a level of knowledge and skill that is sufficient to permit direct engagement in evidence implementation.
Implications for nursing management  Among a range of clinical supports, nurse managers and leaders can contribute to evidence-based health care by understanding the EBP knowledge and skills of their workforce and demanding a more practical approach in nursing education towards evidence-based guidelines and summaries appropriate to the clinical context.     

Technical Aspects of Implantation of LV Lead for Cardiac Resynchronization Therapy in Chronic Heart Failure

The goal of this study was to analyze total procedural and fluoroscopic time during initial experience with implantation of LV lead in a single center, and to assess the performance of electrophysiologically-guided approach for cannulation of the coronary sinus (CS) in a subsequent period. Over an initial period of 29 months, a total of 46 attempts to implant biventricular pacing system were revised. During the first phase, only one type of LV electrode was available for three implanters (11 attempts). The second phase covered their early experience with other stylet-controlled LV leads (10 attempts). Additional LV leads including the over-the-wire design were available in the third phase and 25 attempts were done by he most experienced implanter. In a period of advanced experience, 92 implant procedures performed by four implanters using an electrophysiologically-guided approach to CS cannulation were revised. In the first period, success rates for different phases reached 70%, 90%, and 96%, respectively. Significant decrease in both procedural and fluoroscopic times was achieved with increased experience (Phase I: 247.1 ± 104.5 minutes and 31.2 ± 34.3 minutes, Phase II: 219.4 ± 85.6 minutes, and 22.9 ± 19.1 minutes, Phase III: 116.4 ± 89.9 minutes and 6.6 ± 4.4 minutes, respectively, P < 0.05). Advanced experience with electrophysiologically-guided approach to CS cannulation allowed achievement of this target within a reasonable amount of time (15.4 ± 16.3 minutes) and with minimum fluoroscopic time (2.1 ± 2.9 minutes). In conclusion, both individual learning curve and technical advances significantly influence success rate, procedural, and fluoroscopic times for biventricular system implantation. Electrophysiologically-guided approach makes cannulation of the CS a highly reproducible procedure that requires minimum fluoroscopic time. (PACE 2004; 27[Pt. I]:783–790)