Amidolytic assay of human factor XI in plasma: comparison with a coagulant assay and a new rapid radioimmunoassay

The traditional coagulant assay for plasma factor XI suffers from a relatively high coefficient of variation, the need for rare congenitally deficient plasma, and a poor correlation between precision and sensitivity. We have developed a simple functional amidolytic assay for factor XI in plasma using the chromogenic substrate PyrGlu-Pro-Arg- p-nitroanilide (S-2366). After inactivation of alpha 1-antitrypsin, CI inhibitor, and other plasma protease inhibitors with CHCI3, plasma was incubated with kaolin, in the absence of added calcium, which limited the enzymes formed to those dependent on contact activation. Soybean trypsin inhibitor was used to minimize the action of kallikrein on the substrate. Once the reaction was complete, corn trypsin inhibitor was used to inactive factor XIIa, the enzyme generated by exposure of plasma to negatively charged surfaces, which had activated the factor XI. The assay is highly specific for factor XI, since plasma totally deficient in that zymogen yielded only 1%-3% of the enzymatic activity in normal plasma under identical conditions. The requirements for complete conversion of factor XI to XIa in plasma within 60 min were, respectively, factor XII, 0.6 U/ml, and high molecular weight kininogen, 0.2 U/ml. Prekallikrein was not an absolute requirement for complete activation but did accelerate the reaction. The intraassay coefficient of variation was 3.4%, and the mean of 35 normal plasmas was 1.00 U +/- 0.24 SD. In addition, a new rapid radioimmunoassay was devised using staphylococcal protein A as the precipitating agent for a complex of factor XI antigen with monospecific rabbit antibody. The mean was 1.01 U +/- 0.30 SD. The correlation coefficients for amidolytic versus coagulant and amidolytic versus radioimmunoassay were r = 0.95 for the former and 0.96 for the latter. Thus, a simple, accurate amidolytic assay and a radioimmunoassay have been devised for measuring factor XI in plasma that correlate well with the coagulant activity of factor XI, as determined in our laboratory.     

Prospective health students’ perceptions of the pharmacist role in the interprofessional team

Negative perceptions or underdeveloped understanding of healthcare team member roles can impact the functionality of the team and stunt innovations in interprofessional practice and education. Therefore, the intent of this study was to explore the perception of pharmacists’ role on the healthcare team by future team members: prospective health professional students. The study utilised a survey to examine these perceptions in prospective health professional students (n = 34) nearing the application process to health professional school. A coding process was used to explore open-ended text responses through a line-by-line analysis and identify emerging themes regarding perception of pharmacists’ roles, responsibilities, and practice settings. Quantitative data examined perception of pharmacists by intended prospective profession, healthcare experience, and pharmacy experience. Results indicate that while prospective health professional students find pharmacists to be an important part of the healthcare team, they lack a developed understanding of pharmacists’ roles, responsibilities, and practice settings. Identifying and addressing prospective health professional students’ misperceptions surrounding pharmacists’ roles and responsibilities may encourage them to make informed career decisions and shape them into more knowledgeable future professionals with the ability to better impact patient care on interprofessional teams.     

Induction of proliferation of B prolymphocytic leukemia cells by phorbol ester and native or recombinant interferon-gamma

Phorbol ester phorbol myristate acetate (PMA) induces proliferation in nonmalignant human B cells and B cells from a patient with B prolymphocytic leukemia (B-PLL). Mitogen-free T cell-derived conditioned medium acts synergistically with PMA in inducing proliferation of B-PLL cells but does not enhance the PMA-stimulated outgrowth of nonmalignant B cells. Interleukin 2 (IL-2) has no effect on the outgrowth of B-PLL cells, and monoclonal antibodies against the IL-2 receptor do not influence the response to PMA and conditioned medium. Recombinant interferon-gamma (IFN-gamma), in contrast, is a potent enhancer of PMA-induced proliferation of B-PLL cells. With gel filtration techniques and with the use of anti-IFN-gamma antibodies, it is shown that IFN-gamma in the conditioned medium is responsible for the observed increase in B-PLL cell proliferation. Preincubation of B- PLL cells with IFN-gamma induces responsiveness to PMA, whereas IFN- gamma alone had no effect on these cells when pretreated with PMA. The combined data show that, in the presence of PMA, native and recombinant IFN-gamma are growth factors for B cells from a B-PLL patient and that IL-2 is not involved in this process.     

Lithium chloride: protective and antisecretory properties in rats

Lithium chloride was evaluated as a potential protective agent against ethanol-induced hemorrhagic gastritis in rats. Rats received lithium chloride intragastrically (30, 60, or 90 mg/kg i.g.) or subcutaneously (3, 5, 10, 15, 20, 30, 60, or 90 mg/kg s.c.), or a placebo (H2O i.g. or 0.9% NaCl s.c.). Ninety minutes later 1 cm3 of 95% ethanol was administered intragastrically. After 30 min, the rats were killed and their stomachs were removed and visually scored for gross hemorrhagic gastritis. Lithium chloride at all doses less than 3 mg/kg significantly improved hemorrhagic gastritis when compared with the placebo. Moreover, rats treated with lithium chloride intragastrically had significantly less hemorrhagic gastritis than those treated subcutaneously even though serum lithium levels were similar. To determine if lithium's protective properties related to acid inhibition, pylorus-ligated and gastric fistula rats were studied. The median effective dose for lithium chloride was 20-30 mg/kg and the nonantisecretory dose was 3 mg/kg. No difference in hemorrhagic gastritis was noted between controls and animals receiving the nonantisecretory dose. However, at higher doses (LiCl 30, 60, and 90 mg/kg), lithium's protective properties persisted in spite of adding 150 mM HCl to the intragastrically administered ethanol (p less than 0.001). To determine further if lithium chloride stimulated endogenous prostaglandins, indomethacin, a prostaglandin inhibitor, was administered. Indomethacin did not alter lithium chloride's protective properties. In fact, when compared with exogenously administered 16,16-dimethyl prostaglandin E2 (5 and 500 micrograms/kg), high-dose LiCl (30, 60, or 90 mg/kg) resulted in significantly more protection against ethanol-induced injury (p less than 0.001). In contrast, when both nonantisecretory doses were compared, 16,16-dimethyl prostaglandin E2 (5 micrograms/kg) gave significantly better protection than LiCl (3 mg/kg). These data indicate that LiCl is a potent gastric antisecretory and protective agent. The protective properties of LiCl appear to be related to acid inhibition and be independent of endogenous prostaglandins, although other protective mechanisms may be present at higher LiCl doses. Additionally, this study indicates that LiCl may have clinical application in protecting the gastric mucosa against hemorrhagic gastritis.     

Cigar and pipe smoking related to four year survival of coronary patients.

Six hundred and thirty-four male patients under 60 years who survived a first attack of unstable angina or myocardial infarction were followed for a period of four years. Details of initial and follow-up smoking habits were examined. Patients who continued to smoke cigarettes or cigars had an excess mortality compared with non-smokers, with those who stopped smoking, and with cigarette smokers who changed to pipe smoking. Pipe smokers who continued smoking the pipe had an observed mortality which was greater than that of the non-smokers, but the numbers were small and the results were not statistically significant. The effect of smoking habit on mortality was not influenced by two other determinants of prognosis: age and severity of initial attack. These results confirm that the long-term prognosis of patients after unstable angina or myocardial infarction may be significantly influenced by smoking habits. They are consistent with the hypothesis that cigar and pipe smoking may have an adverse effect after myocardial infarction but further studies are needed to corroborate the association between cigar and pipe smoking and prognosis of coronary heart disease.     

Lack of age-related differences in the clinical presentation of digoxin toxicity.

BACKGROUND--Digoxin toxicity occurs most commonly among the elderly. While the clinical syndrome of digoxin toxicity is well understood, how toxic manifestations change with age is not known. METHODS--We performed secondary analysis of data from a postmarketing surveillance study of patients with life-threatening digoxin toxicity treated with digoxin antibody therapy. Patients receiving long-term maintenance digoxin therapy and aged 55 years or older were divided into four age groups: 55 to 64, 65 to 74, 75 to 84, and 85 years and older (n = 45, 167, 183, and 83, respectively) and compared with regard to presenting manifestations, digoxin dosing, serum potassium and digoxin levels, and renal function. RESULTS--The prevalence of high-degree atrioventricular block showed an increasing but nonsignificant trend with age (40%, 40%, 42%, and 47%, respectively). Age-related trends in high-degree atrioventricular block were stronger among men than women and even stronger among men with underlying cardiac ischemia. The proportion of subjects with nausea/vomiting as a toxic manifestation did not consistently change with age (42%, 48%, 48%, and 46%, respectively). There were no age-related differences in degree of renal impairment or maintenance dose, but maintenance dose decreased with increasing renal impairment. CONCLUSIONS--Among patients with life-threatening digoxin toxicity, there is no age-related difference in clinical presentation.     

Treatment of anal human papillomavirus-associated disease: a long term outcome study

Treatment for human papillomavirus (HPV)-associated anal canal disease has been unsatisfactory. The objective of our study was to determine the treatment outcome in our cohort with anal HPV disease. Overall, 181 patients were evaluated over a median period of 19.1 months (range = 2.8-125.5). Eighty-eight patients (48.6%) with high-grade anal intraepithelial neoplasia (AIN) and 82 patients (45.3%) with low-grade AIN underwent treatment. One hundred and forty-one patients (77.9%) received laser ablative treatment as an outpatient procedure. The treatment yielded cure, defined as a disease-free state at 12 months after treatment, in 63.0% (114/181). Median time to cure for the cohort was 31.5 months (95% confidence interval: 23.0-40.0). Treatment outcome showed no evidence of being affected by age, sexual preference, history of smoking or presence of high-grade disease. Median time to cure was significantly affected by a positive HIV status (P = 0.02) and the extent (volume) of the disease (P = 0.01). Contrary to the current view that treatment of HPV-related anal disease is difficult, unrewarding due to recurrences and may lead to substantial morbidity, we demonstrate that effective treatment is possible for both low- and high-grade AIN. These findings should help with the general desire to introduce screening for AIN for at-risk groups.     

From guidelines to standards of care for open tibial fractures

IntroductionThe standards for the management of open fractures of the lower limb published by the British Association of Plastic, Reconstructive and Aesthetic surgeons (BAPRAS) and British Orthopaedic Association (BOA) were introduced to improve the treatment received by patients after open injury to the lower limb. These Standards were released after BAPRAS/BOA published Guidelines for the management of open tibial fractures.MethodsWe wished to determine the impact of these Standards upon the surgical management of open tibial fractures by comparing patients admitted to an orthoplastic centre in the 45 months concluding December 2009 (the Guidelines era) with those admitted during 2011 (the Standards era). Surgical procedures required during the first 30 days and 12 months after injury were determined. Cases were divided into ‘directly admitted patients’ (DAP) and ‘transferred patients’ (TP). Standards-era patients were divided further into those who had surgery exclusively at the orthoplastic centre (orthoplastic patients (OPP)) and those transferred after surgery (TASP).ResultsThe number of TP trebled in frequency in the Standards era, 25% of whom were transferred before surgery. Significantly fewer surgical procedures were required for DAP and OPP groups compared with TP (and TASP) groups in both eras (Mann–Whitney U-test, p=0.05). DAP and OPP groups during the Standards era underwent the fewest procedures, with the vast majority of cases treated with two or fewer procedures in the first 12 months (88% and 80%, respectively, compared with 61% in the Guidelines era). In the Guidelines era, 44% of TP cases and in the Standards era 39% of TP and 29% of TASP groups underwent two or fewer procedures.Approximately two-thirds of open tibial fractures managed in our orthoplastic centre were patients transferred after surgery. The greatest impact of the Standards was evident for those who underwent surgery exclusively in the orthoplastic centre, reflecting a more deliberate combined strategy.ConclusionThese findings vindicate the Standards as well as mandating reorganisation and resourcing of orthoplastic services to ensure immediate transfer and early combined surgery. By increasing the capacity to deal with time-dependent initial surgery, the surgical burden that the patient must endure, and which the service must provide, are reduced.