Bacterial joint infections in England and Wales: analysis of bacterial isolates over a four year period

Data from 1158 cases of septic arthritis reported to the Public Health Laboratory Service (PHLS) Communicable Disease Control Centre (CDSC) from England and Wales over a 4 yr period (January 1990 December 1993) are presented. Reports where a bacterial organism was isolated from synovial fluid, or where an organism was isolated from blood cultures where a diagnosis of septic arthritis was reported, were examined. Reports of infection were more common in children (12.7% of infections were in the under 10 age group) and the elderly (54.7% aged 60 or over), and were higher in males in all age groups except in the elderly. The most common causative organisms remain staphylococcal and streptococcal species, comprising 40.6% (470) and 28% (324) of cases, respectively. The most common streptococci seen were Streptococcus pneumoniae and Lancefield group A beta-haemolytic Streptococcus organisms, 60.8% (197/324), although group B, C and G organisms accounted for 33.6% of streptococcal isolates (109/324). Haemophilus influenzae septic arthritis is not exclusive to children as 23.2% (16- 69) of cases occurred over the age of 15. A total of 48% (635) of isolates were identified from both synovial fluid and blood cultures, 32.6% (378) from joint fluid alone and 12.5% (146) from blood cultures. Although this study excludes cases of septic arthritis where no organism was isolated, it presents important bacteriological information from a large number of isolates from England and Wales over a 4 yr period. Risk factors identified include a joint prosthesis, joint disease/connective tissue disorder. immunosuppression and diabetes.      

Transformed T lymphocytes infected by a novel isolate of human T cell leukemia virus type II

Human T cell leukemia virus type II (HTLV-II) has been isolated from a patient (Mo) with features of leukemic reticuloendotheliosis (LRE) and from a patient with acquired immunodeficiency syndrome (AIDS). We have obtained another isolate of HTLV-II from a patient (CM) with severe hemophilia A, pancytopenia, and a 14-year history of staphylococcal and candidal infections but no evidence of T cell leukemia/lymphoma, AIDS, or LRE. Fresh mononuclear cells and cultured lymphocytes from CM express retroviral antigens indistinguishable by molecular criteria from HTLV-IIMo. Leukocyte cultures from CM yield hyperdiploid (48,XY, +2, +19) continuous lymphoid lines; human fetal cord blood lymphocytes (CBL) are transformed by cocultivation with these CM cell cultures but retain normal cytogenetic constitution. Electron microscopic examination of the CM cultures and transformed CBL reveals budding of extracellular viral particles, intracellular tubuloreticular structures, and viral particles contained within intracellular vesicles. CM cell cultures and the transformed CBL do not require exogenous interleukin 2, have T cell cytochemical features and mature T helper phenotypes, and exhibit minimal T helper and profound T suppressor activity on pokeweed mitogen-stimulated differentiation of normal B cells. These characteristics, which are similar to those observed with the first HTLV-II isolate, may represent properties of all HTLV-II-infected T cells.     

Tumor necrosis factor-alpha downregulates protein S secretion in human microvascular and umbilical vein endothelial cells but not in the HepG- 2 hepatoma cell line

Protein S deficiency, which is associated with thrombosis, can either be inherited or acquired. Recently, we reported that a decrease in free protein S was observed in 19 of 25 persons with HIV/AIDS. The proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), has been reported to be elevated in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients and has been shown to induce a procoagulant state on the surface of endothelial cells. We report here that recombinant TNF-alpha (rTNF-alpha) downregulated protein S synthesis in the SV-40T transfected human microvascular endothelial cell line (HMEC-1) model system by approximately 70% and in primary human umbilical vein and dermal microvascular endothelial cell cultures by approximately 50%. Using the HMEC-1 model, Northern blot analysis showed a decrease in protein S RNA at 24 hours that was corroborated by Western blot analysis and enzyme- linked immunosorbent assay (ELISA) quantification. Evidence supporting the specificity of the TNF-alpha effect included the following: (1) TNF- alpha down-regulation of protein S was completely blocked by TNF neutralizing antibody; (2) the effect was transient, and protein S was restored to near normal levels after TNF was removed from cell cultures; (3) an antibody directed to the TNF RI (55-kD receptor) was shown to mimic the action of TNF-alpha on HMEC-1 cells; and (4) other proinflammatory cytokines, interleukin (IL)-1, IL-6, and TGF-beta, had no effect on protein S secretion. However, TNF-alpha showed no regulatory control over protein S synthesis in the human hepatocellular carcinoma cell line HepG-2. We suggest that TNF-alpha downregulation of protein S may be a mechanism for localized procoagulant activity and thrombosis recently reported in some AIDS patients with associated protein S deficiency.     

Heart wall velocimetry and exogenous contrast-based cardiac flow imaging in Drosophila melanogaster using Doppler optical coherence tomography

Drosophila melanogaster (fruit fly) is a central organism in biology and is becoming increasingly important in the cardiovascular sciences. Prior work in optical imaging of the D. melanogaster heart has focused on static and dynamic structural anatomy. In the study, it is demonstrated that Doppler optical coherence tomography can quantify dynamic heart wall velocity and hemolymph flow in adult D. melanogaster. Since hemolymph is optically transparent, a novel exogenous contrast technique is demonstrated to increase the backscatter-based intracardiac Doppler flow signal. The results presented here open up new possibilities for functional cardiovascular phenotyping of normal and mutant D. melanogaster.     

Metabolic and energy balance in small- and appropriate-for-gestational-age, very low-birth-weight infants

This study compared nutrient utilization and postnatal weight gain composition in eight appropriate for gestational age (AGA: birth weight 1293 ± 107 g; gestational age 28.8 ± 1.4 weeks) and eight symmetrically growth-retarded (SGA: birth weight 1110 ± 230 g; gestational age 32.7 ± 1.9 weeks), very low-birth-weight (VLBW) infants. There was no significant difference in protein, mineral and energy intake between AGA and SGA infants. Nitrogen absorption (84 ± 3 and 83 ± 4%) and nitrogen retention (356 ± 48 and 352 ± 43 mg/kg/day) were similar in both groups. Fat absorption tended to be lower in AGA (78 ± 15%) than in SGA (87 ± 4%) infants. Calcium, phosphorus and magnesium absorptions were similar in AGA and SGA infants. Metabolizable energy utilization was similar in both groups; about 55% was expended and 45% stored in new tissues. Energy expenditure was 58 ± 4 kcal/kg/day in SGA infants and 61 ± 9 kcal/kg/day in AGA infants. Weight gain and its composition were similar in both groups. We conclude that nutrient and energy utilization are similar in AGA and symmetrically growth-retarded, VLBW infants.     

Determination of flumequine and doxycycline in milk by a simple thin-layer chromatographic method

Tetracycline and quinolone antibiotics have for many years served as important classes of veterinary drugs. Two representatives of both classes: doxycycline from tetracyclines and flumequine from quinolones are often administered together. When the withdrawal periods are not obeyed, the antibiotic residues may be present in edible products, e.g., in meat, eggs or milk. In the present paper a simple thin-layer chromatography (TLC) screening method is established for determining these drugs in milk. Only two developments of the plate with concentrating zone are needed: one as a clean-up procedure, the other as a proper analysis. The spots were detected both by UV lamp with dual wavelength (254 and 366 nm) and by densitometry.