Diversity of in vitro cytokine responses by human macrophages to infection by mycobacterium tuberculosis strains.

Macrophages are an important component in the first line of defence of the innate immune system. They are capable of producing cytokines in response to bacterial challenge, as well as in response to cytokine stimuli from other cells in the immune system. The microbicidal response of human monocyte-derived macrophages in vitro, induced by exogenously added cytokines, is highly variable. We found that tumour necrosis factor-alpha (TNF-alpha) and granulocyte-macrophage colony-stimulating factor (GM-CSF) could have either stimulatory or inhibitory effects on intracellular BCG killing, depending on the macrophage donor. Macrophages infected in vitro by various clinical isolates of Mycobacterium tuberculosis or the laboratory strain H37Rv, produced varying levels of both TNF-alpha and IFN-gamma. Certain M. tuberculosis strains tended to be associated with high cytokine production in each of three independent experiments, indicating that strains may differ in the host response elicited to infection.

Interaction of plasma lipoprotein subfractions with differentiating 3T3-L1 and human mammary preadipocytes in culture.

Differentiating 3T3-L1 preadipocytes (murine fatty fibroblasts) and human preadipocytes interact with human lipoprotein subfractions (HDL2 and LDLII/III) at all stages of the differentiation program, displaying saturable binding behavior. Both cell types interact similarly with LDLII/III as differentiation proceeds, showing increased binding affinities and capacities and maximal rates of uptake in the mature cells, as compared with the preadipocyte stage. These changes coincide with the intracellular appearance of lipid droplets. However, with regard to HDL2, a markedly different pattern of interaction is evident in both cell types. For 3T3-L1 cells, lowered binding and uptake affinities and capacities are apparent in the fully differentiated state for HDL2, as compared with LDLII/III. Human preadipocytes displayed two distinct affinity binding sites for HDL2 during the early stages of differentiation (days 2 and 3), as compared with a single affinity site for LDLII/III at all stages. However, in the fully differentiated human cells, only a single affinity site, indistinguishable from the high-affinity site present on day 2, is evident, and probably represents the only binding site of physiological significance in these cells. All the cellular developments appear to be largely unaffected by exposure of both preadipocyte types to added lipoproteins (HDL + LDL) in the medium during the early stages of the conversion process.

The influence of plasma lipoprotein subfractions on 3T3-L1 and human preadipocyte differentiation in cell culture.

3T3-L1 and human preadipocyte differentiation was significantly (P < 0.001) enhanced by HDL2, LDLII/III and LDLIV. The concentrations of lipoproteins required for maximal differentiation in human preadipocytes were not achieved over the concentration range 50-150 micrograms lipoprotein protein ml-1, whereas maximal differentiation in 3T3-L1 preadipocytes was achieved for all lipoprotein subfractions at approximately 75 micrograms lipoprotein ml-1, a level almost double that required for complete HDL and LDL fractions in 3T3-L1 cells. Despite the enhanced extent of differentiation caused by certain lipoprotein subfractions, the time needed for the conversion process was unaffected. GPDH activity development in both cell types was most pronounced in response to LDLIV, with HDL2 resulting in the lowest activity. In both cell types, the enhancement of differentiation was only evident when the cells were exposed to lipoproteins during the early stage of the program, i.e. before visible formation of lipid droplets.

Improving the prescribing of antibiotics for urinary tract infection.

BACKGROUND: In recent years there have been changes in the recommended antibiotic treatment for urinary tract infections (UTIs). In particular, the use of amoxycillin or co-trimoxazole is now discouraged, with amoxycillin-potassium clavulanate, cephalexin and trimethoprim becoming first-line agents for uncomplicated lower UTIs. AIM: To examine whether academic detailing, performed by a pharmacist, could modify prescribing practices for antibiotics used in the treatment of UTI in the community setting. METHODS: The intervention was conducted in Southern Tasmania, using the remainder of the State as a control area. The target group of general practitioners was sent educational material designed to assist in the appropriate prescribing of antibiotics in the treatment of UTI. A pharmacist then visited each general practitioner and discussed the rational use of antibiotics for UTIs directly with him/her. Outcomes were measured using evaluation feedback from the general practitioners and pharmacoepidemiological data, which were not linked to diagnosis. The key variable examined was the total defined daily doses (DDDs) dispensed for the recommended first-line agents (amoxycillin-potassium clavulanate, cephalexin and trimethoprim) compared with amoxycillin (3 g single-dose form) and co-trimoxazole. RESULTS: The educational programme was very well received by the general practitioners. Changes in the prescribing of antibiotics commonly used for UTIs were evident in both study regions over the course of the study, but the improvements were significantly greater in the intervention area. CONCLUSION: Educational programmes utilizing academic detailing by pharmacists can modify prescribing practices within the community setting.

Effect of lipoproteins on the differentiation of 3T3-L1 and human preadipocytes in cell culture.

High-density and low-density lipoprotein (LDL) stimulated 3T3-L1 and human preadipocyte differentiation in vitro. In both cell types, LDL exhibited the greatest stimulatory effect. LDL suppressed the development of catecholamine-stimulated lipolysis in differentiating 3T3-L1 and human preadipocytes when present during preadipocyte proliferation and early stages of differentiation. The effect of lipoproteins on development of human preadipocyte (but not 3T3-L1) lipolysis may involve beta-adrenoceptors.

Improving drug use in rheumatic disorders.

A recent study concluded that approximately 50 elderly people are admitted to the major teaching hospital in Tasmania, Australia each year suffering from gastrointestinal bleeding related to the use of nonsteroidal anti-inflammatory drugs (NSAIDs). The aim of this study was to examine whether academic detailing, designed to encourage a rational approach to the prescribing of NSAIDs and performed by a pharmacist; could modify prescribing practices in the community. The intervention was conducted in Southern Tasmania, using the north of the state as a control area. The target group of all general practitioners (approximately 250) working in Southern Tasmania was sent educational material designed to assist in the appropriate prescribing of NSAIDs. A pharmacist then visited each general practitioner and discussed the rational use of NSAIDs directly with them. The outcome of the programme was measured using evaluation feedback from the general practitioners and pharmacoepidemiological data provided by (i) a state-wide pharmacoepidemiology database derived from community pharmacy records, and (ii) dispensing under the Pharmaceutical Benefits and Repatriation Pharmaceutical Benefits Schemes. The key variable examined was the defined daily dose (DDD) dispensed for the NSAIDs compared with paracetamol. The educational programme was very well received by the general practitioners. Changes in the prescribing of NSAIDs were evident in both study regions, but were more marked in the intervention area. For instance, the state-wide pharmacoepidemiological database indicated that the ratio of dispensed DDDs of NSAIDs: paracetamol declined from 3.00 to 2.59 in the intervention region and remained steadier (3.16 to 2.92) in the north of the state. The improvement was significantly greater in the intervention region. This study has revealed that an educational programme utilizing academic detailing by pharmacists can modify prescribing practices within the community setting.

Drug-related admissions to an Australian hospital.

This study was conducted to determine the prevalence of drug-related hospital admissions in southern Tasmania, Australia. The causes of consecutive admissions to medical wards of the Royal Hobart Hospital were reviewed. Comprehensive data were collected over a 10-week period on 691 admissions (median age: 67 years and range: 11-97 years; 50.8% males). Sixty-eight (9.8%) of the admissions were classified as being either probably or definitely drug-related. Most of these admissions were attributable to intentional overdose (38.2%) or an adverse drug reaction (30.9%). The overdoses often involved benzodiazepines or antipsychotics. Gastrointestinal bleeding related to the use of nonsteroidal anti-inflammatory drugs was the most common adverse drug reaction (38.1% of all reactions). Other drug-related admission categories were poor compliance (14.7%), dosage decrease or therapy cessation by a doctor producing an exacerbation of symptoms (7.4%), substance abuse (4.4%) and drug interaction (4.4%). Patients with a drug-related admission were, on average, younger than the other medical admissions, with no significant difference in gender. Patients admitted due to an overdose or substance abuse were younger than other drug-related admissions and non-drug related admissions. In conclusion, this study has determined that almost 10% of medical admissions to the hospital are drug-related and it is estimated that 40 to 50 elderly people are admitted each year suffering from gastrointestinal bleeding related to nonsteroidal anti-inflammatory drugs.

Kinetic properties of ovine adipose tissue fructose-1,6-bisphosphatase.

The presence of FBPase was confirmed in both human and ovine white adipose tissue in metabolically significant amounts. The partially purified enzyme from ovine adipose tissue exhibited kinetic properties very similar to other mammalian FBPases (pH optimum of 7.5, absolute requirement for divalent metal ions and strong inhibition by both AMP and F-2,6-P2). The micromolar S0.5 value obtained suggests that the enzyme may be of physiological significance.