Early experience with laparoscopic herniorrhaphy: results after the first 60 procedures.

The results of the first 60 consecutive laparoscopic hernia repairs performed in Calderdale are presented. These results are encouraging as recovery from surgery is much quicker and allows a shorter hospital stay and a speedier return to work than conventional operations. The laparoscopic procedure takes longer to perform, although this does not seem unacceptable once experience is gained. At present it remains quite expensive and further reductions in hospital stay will need to be achieved to ensure that there is no overall increase in the financial resources required.     

Use of an improved quantitative polymerase chain reaction assay to determine differences in human rhinovirus viral loads in different populations

Human rhinoviruses (HRV) frequently cause acute respiratory infections and chronic respiratory disease exacerbations. However, testing is not generally offered. We developed a modified HRV quantitative polymerase chain reaction (qPCR) assay to assess viral loads in the community and hospital patients. The assay had a lower limit of detection of 2 log₁₀ viral copies/mL and displayed linearity over 5 log₁₀ viral copies, with a lower limit of quantitation of 4 log₁₀ viral copies/mL. Mean viral loads (95% confidence interval) for hospitalized children, university students, and institutionalized elderly, were 7.08 log₁₀ viral copies/mL (6.7–7.5), 6.87 log₁₀ viral copies/mL (6.5–7.2), and 7.09 log₁₀ viral copies/mL (6.9–7.3), respectively (P = 0.67). Serial specimens of 14 university students showed a decrease of mean viral loads from 6.36 log₁₀ viral copies/mL on day 1 to 2.32 log₁₀ viral copies/mL 7 days past symptom onset (P < 0.001). Using an HRV qPCR, we showed that viral loads did not differ between the community and hospitalized populations and significantly decreased following symptoms onset in healthy individuals.     

The effect of dietary restriction on mitochondrial protein density and flight muscle mitochondrial morphology in Drosophila

Dietary restriction (DR) extends life span in diverse organisms and may do so by attenuating production of mitochondrial reactive oxygen species (ROS). However, measurements of ROS production from isolated mitochondria of organisms subjected to DR have produced inconsistent results. In the fruit fly Drosophila, DR does not reduce production of ROS from isolated mitochondria. In this study, we used Drosophila to test whether DR lowered mitochondrial density. We assessed mitochondrial densities of flies on DR and Control diets using (a) the activities of mitochondrial enzymes and (b) electron microscopy. Both methods showed no overall effect of DR on mitochondrial density; however, mitochondrial enzyme activities and morphology differed significantly between DR and Control flies. We concluded that life-span extension by DR in Drosophila is not mediated through a reduction in mitochondrial density. If DR in Drosophila extends life span by reducing ROS production, then it does so through mechanisms that operate only in vivo.     

Rifapentine and isoniazid in the continuation phase of a 6-month regimen. Final report at 5 years: prognostic value of various measures.

SETTING: Clinical trial in 672 patients with newly diagnosed pulmonary tuberculosis in Hong Kong. After an initial 2 months of a four-drug intensive phase consisting of thrice-weekly streptomycin, isoniazid, rifampicin and pyrazinamide (SHRZ), a random allocation was made to a continuation phase of once-weekly 600 mg rifapentine + 15 mg/kg isoniazid (HRp1), HRp1 given in 2 of every 3 weeks (HRp1.2/3), or to thrice-weekly isoniazid + rifampicin (HR3), the standard treatment in Hong Kong. OBJECTIVE: Final report evaluating adverse events (46 relapses and one failure) after 5 years and the prognostic influence of various factors. METHODS: Kaplan-Meier analysis of adverse events and Cox proportional hazards analysis of prognostic factors. RESULTS: The two rifapentine regimens, HRp1 and HRp1.2/3 had similar final rates of adverse events of 10.8% and 11.7%, respectively, compared to 4.2% for the HR3 regimen (P = 0.02 and 0.009, respectively). In the initial univariate proportional hazards analysis, adverse events were significantly related to the regimen, age, sex, pretreatment radiographic extent of disease and cavitation, and also to sputum culture at 2 months. In the final multivariate analysis, after step-wise removal of non-significant factors, adverse events were related only to the regimen, patients' sex and pretreatment radiographic extent of disease. Elderly male patients were more at risk of an adverse event, as were those with more severe disease. Adverse events occurred at life table rates of 9.0% in patients with drug-sensitive strains and in 8.9% of those with initially isoniazid-resistant organisms at 5 years. CONCLUSIONS: The two rifapentine regimens were unsatisfactory because of their high incidence of adverse events. Isoniazid appeared not to contribute to preventing relapse. Further studies with increased rifapentine dosage are necessary.     

心房颤动的电生理重构

心房颤动 (atrial fibrillation,AF)是临床上最常见的一种持续性心律失常 ,其发病率随年龄而增加 ,40岁以下人群发病率约为 0 .2 %～ 0 .3% ,6 0～ 90岁年龄组发病率增至5 %～ 9% [1 ] 。新近 Framingham的研究表明 AF可以成为一种独立的因素使患者病死率增加 [2 ] 。 AF的发病机制尚未完全清楚 ,可能为非单一机制 ,普遍认为持续性 AF是由于心房内的多子波折返 ,每 1个折返环本身都在不停地改变其大小及传导方向。近年来 ,在 AF的基础及临床研究中 ,两个方面的进展具有十分重要的意义 :一是发现部分 AF起源于心房内某些部位如肺静脉口…     

Platelet-leukocyte cross talk in whole blood

Thrombosis and inflammation involve complex platelet-leukocyte interaction, the details of which are not fully elucidated. Therefore, we investigated cross talk between platelets and leukocytes in whole blood, under the following physiological conditions: at 37 degrees C, with normal calcium concentrations, and with shear force. Platelet P-selectin and leukocyte CD11b expression were used to monitor platelet and leukocyte activation, respectively, and platelet-leukocyte aggregation (PLA) was analyzed. The leukocyte-specific agonist N:-formyl-methionyl-leucyl-phenylalanine (10(-6) mol/L) increased P-selectin-positive platelets from 2.5+/-0. 1% to 5.1+/-0.6% (P:<0.05). The increase was inhibited by either the platelet-activating factor (PAF) antagonist SR27417, the superoxide anion scavenger superoxide dismutase, the 5-lipoxygenase inhibitor Zileuton, or the 5-lipoxygenase-activating protein inhibitor MK-886, suggesting the involvement of PAF, superoxide anion, and 5-lipoxygenase products in leukocyte-induced platelet activation. The platelet-specific agonist collagen (1 microg/mL) increased leukocyte CD11b expression from 2.94+/-0.52 to 3.81+/-0.58 (P:<0. 05); this was not inhibited by the thromboxane A(2) receptor antagonist ICI 192.605 or the PAF antagonist SR27417. Platelet P-selectin expression induced by N:-formyl-methionyl-leucyl-phenylalanine and leukocyte CD11b expression induced by collagen could be suppressed by glycoprotein IIb/IIIa blockade or P-selectin blockade. This study documents platelet-leukocyte cross talk under conditions that mimic a physiological state and suggests that this involves multiple mediators and mechanisms. Furthermore, new evidence of integrin and selectin involvement in intracellular and intercellular signaling during platelet-leukocyte cross talk is provided.     

Increased binding of fibrinogen to glycoprotein IIIa-proline33 (HPA-1b, PlA2, Zwb) positive platelets in patients with cardiovascular disease.

AIMS: The GPIIb-IIIa complex on the platelet membrane plays an important part in thrombosis as it is the receptor for fibrinogen. The gene for platelet membrane glyco-protein IIIa has multiple alleles one of which, the GPIIIa-Proline33 (HPA-1b, PlA2, Zwb) allele has been reported in some, but not all studies, to be associated with an increased risk of myocardial infarction. We investigated whether the presence of the Pro33 form of GPIIIa on the platelet membrane is associated with increased fibrinogen binding. METHODS AND RESULTS: Blood samples from 70 patients (54 male) with stable angina of whom 22 (18 male) had a history of previous myocardial infarction, were analysed for the GPIIIa-Leu-Pro33 polymorphism at the genomic level, and for whole blood flow cytometric measurement of platelet fibrinogen binding. The GPIIIa-Pro33 form was present in 20 (28.6%) patients (1 homozygous) representing an allele frequency of 0.85 and 0.15 (GPIIIa-Leu33:Pro33). The incidence of myocardial infarction was higher (40.0%) in patients positive for GPIIIa-Pro33 than in those without (32.0%) but this was not significant (P=0.58). Fibrinogen binding to ADP-stimulated platelets was significantly higher in the GPIIIa-Pro33 positive group at all ADP concentrations (<0.0001; two way ANOVA). There was no association between fibrinogen binding and the level of expression of the GPIIb-IIIa complex, platelet volume or platelet count. Fibrinogen binding in response to thrombin stimulation was not different between the groups (P>0.05). CONCLUSIONS: The increased tendency of platelets from patients with the Pro33 form of GPIIIa may predispose patients with this allele to a higher risk of acute thrombotic events, and argues for selective use of therapeutic agents that inhibit ADP-mediated platelet activation in occlusive vascular disease states.     

Comparison of the release of microRNAs and extracellular vesicles from platelets in response to different agonists

On activation platelets release microRNAs and extracellular vesicles (EV) into circulation. The release of EV from platelets has been shown to be dependent on the agonist; in this study, we investigated whether the microRNA profile or EV released from platelets was also agonist specific.

Washed platelets from healthy subjects were maximally stimulated with agonists specific for the receptors for collagen (Glycoprotein VI (GPVI)), thrombin (PAR1/PAR4), or ADP (P2Y1/P2Y12) with/without inhibiting secondary mediators, using aspirin to block cyclooxygenase-1 and apyrase to remove ADP. The released microRNAs were profiled using TaqMan microRNA microarray cards. Platelet-derived EV (pdEV) were characterized by size (Nanoparticle Tracking Analysis, NTA), for procoagulant activity (Annexin-V binding and support of thrombin generation), and for the EV markers CD63 and HSP70.

Platelet activation triggered the release of 57–79 different microRNAs, dependent upon agonist, with a core of 46 microRNAs observed with all agonists. There was a high level of correlation between agonists (r² > 0.98; p < 0.0001 for all), and with the microRNA content of the parent platelets (r² > 0.98; p < 0.0001). The 46 microRNAs seen in all samples are predicted to have significant effects on the translation of proteins involved in endocytosis, cell cycle control, and differentiation. MiR-223-3p was the most abundant in all samples and has previously been implicated in myeloid lineage development and demonstrated to have anti-inflammatory effects. Stimulation through GPVI produced a pdEV population with significantly more procoagulant activity than the other agonists. Apyrase significantly reduced microRNA and pdEV release, while aspirin had little effect.

These data suggest that all tested agonists trigger the release of a similar microRNA profile while the procoagulant activity of the pdEV was agonist dependent. ADP was shown to play an important role in the release of both microRNAs and pdEV.     

Patient perspectives on de‐simplifying their single‐tablet co‐formulated antiretroviral therapy for societal cost savings

Objectives

The incremental costs of expanding antiretroviral (ARV) drug treatment to all HIV‐infected patients are substantial, so cost‐saving initiatives are important. Our objectives were to determine the acceptability and financial impact of de‐simplifying (i.e. switching) more expensive single‐tablet formulations (STFs) to less expensive generic‐based multi‐tablet components. We determined physician and patient perceptions and acceptance of STF de‐simplification within the context of a publicly funded ARV budget.

Methods

Programme costs were calculated for patients on ARVs followed at the Southern Alberta Clinic, Canada during 2016 (Cdn$). We focused on patients receiving Triumeq® and determined the savings if patients de‐simplified to eligible generic co‐formulations. We surveyed all prescribing physicians and a convenience sample of patients taking Triumeq® to see if, for budgetary purposes, they felt that de‐simplification would be acceptable.

Results

Of 1780 patients receiving ARVs, 62% (n = 1038) were on STF; 58% (n = 607) of patients on STF were on Triumeq®. The total annual cost of ARVs was $26 222 760. The cost for Triumeq® was $8 292 600. If every patient on Triumeq® switched to generic abacavir/lamivudine and Tivicay® (dolutegravir), total costs would decrease by $4 325 040. All physicians (n = 13) felt that de‐simplifying could be safely achieved. Forty‐eight per cent of 221 patients surveyed were agreeable to de‐simplifying for altruistic reasons, 27% said no, and 25% said maybe.

Conclusions

De‐simplifying Triumeq® generates large cost savings. Additional savings could be achieved by de‐simplifying other STFs. Both physicians and patients agreed that selective de‐simplification was acceptable; however, it may not be acceptable to every patient. Monitoring the medical and cost impacts of de‐simplification strategies seems warranted.

     

Book reviews

Myointima formation or intimal hyperplasia is a major undesirable problem at the anastomotic ends of narrow bore arterial autografts and in other arterial wall injuries, which often leads to late restenosis and thrombosis and whose pathogenesis is still not understood. Platelets are suspected to intervene at some stages of its development, together with endothelial and muscle cells, the extracellular matrix and, most probably, adhesion receptors. To ascertain whether and at what stage beta 3 integrins are involved, a rat arterial autograft model was used, together with monoclonal antibody P37, which is directed to the sequence 101-109 of the beta 3 subunit of the human platelet fibrinogen receptor integrin alpha IIb beta 3 and inhibits platelet aggregation in vitro and acute thrombosis in vivo . Three groups of animals were used: group I underwent an arterial autograft of a 5-mm segment of the right common iliac artery; group II received, intravenously, a single dose 0.8 mg kg of P37 at 15 min before the graft implantation; and group III was treated as group II but a similar dose of antibody was additionally given on day 14 after the operation. Animals in each group were sacrificed on days 7, 14, 21, 30 and 50 after the operation, and the grafts were removed for light and electron microscopy observation and further time-dependent morphometric analysis. By day 14, group I autografts already showed intimal hyperplasia and secretory smooth muscle cells, while group II and II autografts presented only some degenerative changes in the medial layer, with no signs of hyperplasia. Intimal hyperplasia was observed on day 21 in group II and on day 30 in group III, although less pronounced than in the corresponding controls. However, by day 50, the three groups had the same thickness of myointima. The immunohistochemical determination of metalloproteases suggests no role for these enzymes in the immunoinhibition of myointima formation. We conclude that P37 inhibits the onset of the intimal hyperplasia in the arterial autografts and that this onset in treated animals seems to be related to the decay of the circulating antibody. Further work is required to decide whether a higher or longer presence of circulating P37 can definitively prevent the development of intimal hyperplasia, as well as to ascertain which cells and which beta 3 integrin receptors intervene.