Investigation of melt agglomeration process with a hydrophobic binder in combination with sucrose stearate

The melt agglomeration process of lactose powder with hydrogenated cottonseed oil (HCO) as the hydrophobic meltable binder was investigated by studying the physicochemical properties of molten HCO modified by sucrose stearates S170, S770 and S1570. The size, size distribution, micromeritic and adhesion properties of agglomerates as well as surface tension, contact angle, viscosity and specific volume of molten HCO, with and without sucrose stearates, were examined. The viscosity, specific volume and surface tension of molten HCO were found to be modified to varying extents by sucrose stearates which are available in different HLB values and melt properties. The growth of melt agglomerates was promoted predominantly by an increase in viscosity, an increase in specific volume or a decrease in surface tension of the molten binding liquid. The agglomerate growth propensity was higher with an increase in inter-particulate binding strength, agglomerate surface wetness and extent of agglomerate consolidation which enhanced the liquid migration from agglomerate core to periphery leading to an increased surface plasticity for coalescence. The inclusion of high concentrations of completely meltable sucrose stearate S170 greatly induced the growth of agglomerates through increased specific volume and viscosity of the molten binding liquid. On the other hand, the inclusion of incompletely meltable sucrose stearates S770 and S1570 promoted the agglomeration mainly via the reduction in surface tension of the molten binding liquid with declining agglomerate growth propensity at high sucrose stearate concentrations. In addition to being an agglomeration modifier, sucrose stearate demonstrated anti-adherent property in melt agglomeration process. The properties of molten HCO and melt agglomerates were dependent on the type and concentration of sucrose stearate added.     

Quantitative measurement of lead in paint by XRF analysis without manual substrate correction

X-ray fluorescence analysis has been used for measurement of lead in paint for more than a decade. The early systems provided a nondestructive alternative technology to laboratory-based technologies, but were somewhat time consuming and often led to inconclusive results. The procedure required manual substrate correction, multiple measurements, operator's discretion in validating a measurement due to interfering elements and laboratory analysis of inconclusive samples. A new instrument, the RMD LPA-1 system, has been developed based on X-ray fluorescence technology that addresses all of the drawbacks to the older systems. This new system uses a carefully designed and controlled geometry and modern microprocessor technology to automatically provide a rapid quantitative measurement of lead in paint with a 95% confidence level. The improved precision and accuracy achieved with this system are due to geometric enhancements and a mathematical approach which incorporates corrections for both random and systematic errors such as matrix effects and Compton scatter. This technology has been incorporated in a hand-held X-ray fluorescence lead paint analyzer system. A key design philosophy for this system was to maintain a very narrow, task-specific focus, the system was not designed to be an all purpose XRF analyzer, rather it is optimized to meet regulatory requirements of lead paint testing in the most efficient manner. The development of the LPA-1 system is an example of what can be accomplished by listening to the needs and desires of the users, rethinking the design of an existing technique and incorporating modern microprocessor technology.     

Bidirectional diode gate: application as a neural spike enhancer

Summary An inexpensive instrument has been described that may be used to eliminate noise in low-level nerve recordings. This electronic manipulation of such signals increases the reliability of digitising or illustrating neural events while eliminating ambiguous noise levels.     

Studies in the enhancement of tumour immunity by coupling strong antigens to tumour cells (''heterogenization of tumours''). Helper T cell clones against PPD help other T cells mount anti-tumour responses to PPD-coupled tumour cells

PPD-reactive T cell clones have been used to analyse the nature of T lymphocytes that are involved in the 'heterogenization' of tumour cells. This is a phenomenon where coupling tumour cells to a strong antigen (in this case PPD) causes an enhanced immune response to tumour-specific antigens to be elicited providing that the host shows T cell immunity to the strong antigen (in this case is BCG positive). Clones of T cells with the Lyt1+2- phenotype which were unable to mediate delayed-type hypersensitivity but which provided efficient help to hapten-primed B cells were found to potentiate anti-tumour immunity in BCG-negative syngeneic mice when immunized with Con-A-PPD coupled, X-irradiated MC6A tumour cells. There therefore appears to be a mechanism whereby a helper T cell response to one antigen can provide help for the generation of a T cell response to a linked antigen which is analogous to the well-known phenomenon of help to hapten primed B cells. Furthermore the clones of T cells that help B cells the best are those that give maximal augmentation of T cell immunity.     

New strategies for prevention and therapy of cytomegalovirus infection and disease in solid-organ transplant recipients

In the past three decades since the inception of human organ transplantation, cytomegalovirus (CMV) has gained increasing clinical import because it is a common pathogen in the immunocompromised transplant recipient. Patients may suffer from severe manifestations of this infection along with the threat of potential fatality. Additionally, the dynamic evolution of immunosuppressive and antiviral agents has brought forth changes in the natural history of CMV infection and disease. Transplant physicians now face the daunting task of recognizing and managing the changing spectrum of CMV infection and its consequences in the organ recipient. For the microbiology laboratory, the emphasis has been geared toward the development of more sophisticated detection assays, including methods to detect emerging antiviral resistance. The discovery of novel antiviral chemotherapy is an important theme of clinical research. Investigations have also focused on preventative measures for CMV disease in the solid-organ transplant population. In all, while much has been achieved in the overall management of CMV infection, the current understanding of CMV pathogenesis and therapy still leaves much to be learned before success can be claimed.     

Multiple-injection axillary brachial plexus block: A comparison of two methods of nerve localization-nerve stimulation versus paresthesia

We conducted this prospective study to compare the onset time and the success rate of a multiple-injection axillary brachial plexus block performed by using two methods of nerve localization: paresthesia elicitation or nerve stimulation. Each of the major nerves of the plexus was located by elicitation of a paresthesia (Group PAR; n = 50) or by nerve stimulation (Group PNS; n = 50) and injected with 10 mL of local anesthetic solution. Time to perform the block, onset time of the primary block, time to achieve readiness for surgery, and total anesthetic time were significantly shorter in Group PNS than in Group PAR. The incidence of complete block was larger in Group PNS than in Group PAR (91% vs 76%; P: < 0. 05), and this was related to a larger success rate for anesthetizing the radial and the musculocutaneous nerves (P: < 0.05). The frequency of venous puncture was larger in Group PAR (P: < 0.05). For multiple-injection axillary brachial plexus block, we conclude that nerve stimulation resulted in a greater success rate and a faster onset than paresthesia elicitation, and it should be considered when the radial and musculocutaneous nerve distributions are involved in the surgical area. IMPLICATIONS: Two methods of nerve localization were compared when performing an axillary brachial plexus block by the multiple-injection technique. Nerve stimulation provided a faster onset and a greater incidence of complete block, related to a better success rate for anesthetizing the radial and the musculocutaneous nerves, than paresthesia elicitation.     

A comparison of patient-controlled epidural analgesia following gynaecological surgery with and without a background infusion

We conducted a randomised, controlled study to investigate the effect of adding a background infusion to patient-controlled epidural analgesia for postoperative pain relief. Forty-two patients scheduled for elective lower abdominal gynaecological surgery received patient-controlled epidural analgesia postoperatively using a mixture of 0.2% ropivacaine and 2.0 microg x ml-1 fentanyl. Patients in group B (n = 20) were given a background infusion of 5 ml x h-1, whereas those in group N (n = 21) were not. There was no difference in pain scores or patient satisfaction scores between the two groups. Patients in group B had a higher total drug consumption (156.8 +/- 34.8 ml vs. 89.5 +/- 41.0 ml; p < 0.0001) and incidence of side-effects (71.4% vs. 30.0%; p = 0.007). Motor blockade during the 24-h study period was also greater in group B (median [range] area under the curve 7.5 [0.0-39.0] h vs. 3.0 [0.0-36.0] h; p = 0.035). We conclude that the addition of a background infusion to patient-controlled epidural anaesthesia is not recommended as it confers no additional benefits.     

The effect of the addition of ropivacaine or bupivacaine upon pruritus induced by intrathecal fentanyl in labour

Sixty patients in early labour were randomly allocated to one of three groups. The control group received intrathecal fentanyl 25 microg, the ropivacaine group received intrathecal fentanyl 25 microg and ropivacaine 2.5 mg while the bupivacaine group received intrathecal fentanyl 25 microg and bupivacaine 2.5 mg. The incidence of pruritus was 100% in controls, compared with 85% in the ropivacaine group (not significant) and 75% in the bupivacaine group (p = 0.003). The severity of pruritus was significantly less in the ropivacaine (p = 0.006) and bupivacaine (p = 0.001) groups. Most patients developed pruritus by 30 min. Pruritus above the abdomen was not reduced in patients receiving local anaesthetics. There were no significant differences in the mean pain visual analogue score, systolic blood pressure, maternal heart rate and upper level of reduced pin-prick sensation in the first 30 min. Intrathecal ropivacaine and, more so, intrathecal bupivacaine reduce the incidence and severity of pruritus from intrathecal fentanyl for labour analgesia.     

A meta-summary of case reports of non-vitamin K antagonist oral anticoagulant use in patients with left ventricular thrombus

Left ventricular (LV) thrombus is commonly seen in patients with extensive anterior ST-elevation myocardial infarction. The standard of care for LV thrombus is anticoagulation with warfarin. However, there has been an increasing trend of case reports using non-vitamin K antagonist oral anticoagulants (NOAC) for the treatment of LV thrombus. This study aimed to perform a meta-summary of the literature to characterise and evaluate the safety and feasibility of using NOAC in patients with LV thrombus. We searched for articles published in four electronic databases: PubMed, EMBASE, Scopus and Google Scholar using an appropriate keyword/MeSH term search strategy. Twenty-four studies comprising 36 patients were included in the analysis. Rivaroxaban was used in majority of patients (47.2%), whilst Apixaban and Dabigatran were prescribed in 25.0% and 27.8% of patients respectively. The most commonly associated risk factor found was post-acute myocardial infarction in 15 patients (41.7%). LV thrombus resolution was met by most patients (87.9%), and the median duration of treatment to resolution was 30.0 days (IQR?=?22.5–47.0). One non-fatal bleeding event (3.0%) and no embolic events were reported. The use of NOAC may have a role in the treatment of LV thrombus in selected patients. Further randomized controlled trials are needed to evaluate this treatment strategy.