Using technology to reduce critical deterioration (the DETECT study): a cost analysis of care costs at a tertiary children's hospital in the United Kingdom

BACKGROUND

Electronic early warning systems have been used in adults for many years to prevent critical deterioration events (CDEs). However, implementation of similar technologies for monitoring children across the entire hospital poses additional challenges. While the concept of such technologies is promising, their cost-effectiveness is not established for use in children. In this study we investigate the potential for direct cost savings arising from the implementation of the DETECT surveillance system.

METHODS

Data were collected at a tertiary children's hospital in the United Kingdom. We rely on the comparison between patients in the baseline period (March 2018 to February 2019) and patients in the post-intervention period (March 2020 to July 2021). These provided a matched cohort of 19,562 hospital admissions for each group. From these admissions, 324 and 286 CDEs were observed in the baseline and post-intervention period, respectively. Hospital reported costs and Health Related Group (HRG) National Costs were used to estimate overall expenditure associated with CDEs for both groups of patients.

RESULTS

Comparing post-intervention with baseline data we found a reduction in the total number of critical care days, driven by an overall reduction in the number of CDEs, however without statistical significance. Using hospital reported costs adjusted for the Covid-19 impact, we estimate a non-significant reduction of total expenditure from £16.0 million to £14.3 million (corresponding to £1.7 million of savings - 11%). Additionally, using HRG average costs, we estimated a non-significant reduction of total expenditure from £8.2 million to £ 7.2 million (corresponding to £1.1 million of savings - 13%).

DISCUSSION AND CONCLUSION

Unplanned critical care admissions for children not only impose a substantial burden on patients and families but are also costly for hospitals. Interventions aimed at reducing emergency critical care admissions can be crucial to contribute to the reduction of these episodes' costs. Even though cost reductions were identified in our sample, our results do not support the hypothesis that reducing CDEs using technology leads to a significant reduction on hospital costs.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN61279068, date of registration 07/06/2019, retrospectively registered.

Health service COVID-19 wellbeing and support initiatives: a mixed-methods evaluation

BACKGROUND

Health services implemented a range of initiatives during the COVID-19 pandemic to support employee wellbeing and assist employees to manage the professional and personal challenges they experienced. However, it is not known if such initiatives were acceptable to employees or met their needs.

AIMS

To evaluate the wellbeing and support initiatives implemented at an Australian health service during the COVID-19 pandemic from the perspectives of employees (both users and non-users) and key stakeholders.

METHODS

A mixed-methods design (survey, interviews and data audit) to investigate employees' and key stakeholders' perceptions, experiences and use of the wellbeing and support initiatives implemented at a large tertiary metropolitan health service in Melbourne, Australia.

RESULTS

Ten employees participated in an interview and 907 completed a survey. The initiatives were well used and appreciated by staff. There was no significant difference in the proportion of clinical staff who had used the initiatives compared to non-clinical staff (44% versus 39%; P=0.223). Survey respondents reported the initiatives improved their mental health (n = 223, 8%), ability to cope with COVID-19 related stress and anxiety (n = 206, 79%), do their work (n = 200, 77%) and relationships with colleagues (n = 174, 67%). Staff would like many of the initiatives (with some modifications) to continue after the COVID-19 pandemic.

CONCLUSIONS

The findings suggest a high level of staff satisfaction with the implemented wellbeing and support initiatives, and confirm the need for, and importance of, developing and implementing initiatives to support health service staff during outbreaks of infectious diseases such as the COVID-19 pandemic.

A Survey of Latent Tuberculosis Screening and Treatment Practices in a Tertiary Centre

Aim Knowledge of latent tuberculosis infection (LTBI) screening and treatment practices are lacking in Ireland, where LTBI is not programmatically surveyed or managed. The aim of this research was to describe current clinical practice when screening and treating patients for LTBI in a tertiary referral centre in Ireland. Methods A 17-question survey relating to LTBI screening and management practices with both open-ended questions and close ended multiple-choice questions was created using SurveyMonkey. The survey target sample was healthcare workers in the tertiary centre who direct LTBI screening and treatment for patients at risk of TB disease in their respective departments. Results The response rate to the survey was 45% (21/47). Seventy-one percent (15/21) of those surveyed responded to the question "What barriers exist to screening patients for latent TB in your clinical practice?". Fifty-three percent (8/15) said that they found it difficult to access LTBI testing and 27% (4/15) cited accessing the interferon-gamma release assay (IGRA) result as a barrier. Forty-three percent (9/21) responded that there was not a clear referral pathway for patients that they would like specialist input on when diagnosing and managing patients with LTBI. Conclusion Access to LTBI testing, LTBI test results, TB specialist services and the use of rifamycin-based regimens should be improved in this tertiary centre. Consideration should be given to developing a national LTBI education programme for healthcare professionals and updating national LTBI treatment guidelines.

Effectiveness of interferon-free therapy for the treatment of HCV-patients with compensated cirrhosis treated through the Irish early access program

BACKGROUND

We investigated the real-world effectiveness of interferon-free regimens for the treatment of patients with compensated cirrhosis infected with hepatitis C virus (HCV).

METHOD

Using the Irish national HCV treatment registry, the effectiveness and safety of interferon-free regimens for HCV-infected patients treated between April 2015 and August 2016, was determined.

RESULTS

A SVR12 was achieved in 86% of subjects treated with sofosbuvir/ledipasvir ± ribavirin (SOF/LDV±RBV), 93% treated with paritaprevir, ombitasvir and ritonavir combined with dasabuvir ± ribavirin (3D±RBV) and 89% treated with sofosbuvir/daclatasvir ± ribavirin (SOF/DCV±RBV). The discontinuation rate was 5% and the on-treatment mortality rate was 1%.

CONCLUSION

The availability of interferon-free regimens represents a significant breakthrough for the treatment of HCV infection. Treatments options, with high SVR12 rates, are now available for patients with compensated cirrhosis who were unsuitable for treatment with interferon-based regimens. Data obtained from studies conducted in real world practice provide robust information fundamental for input into future economic evaluations for agents used for the treatment of HCV infection.

pRotective vEntilation with veno-venouS lung assisT in respiratory failure: A protocol for a multicentre randomised controlled trial of extracorporeal carbon dioxide removal in patients with acute hypoxaemic respiratory failure

One of the few interventions to demonstrate improved outcomes for acute hypoxaemic respiratory failure is reducing tidal volumes when using mechanical ventilation, often termed lung protective ventilation. Veno-venous extracorporeal carbon dioxide removal (vv-ECCO₂R) can facilitate reducing tidal volumes. pRotective vEntilation with veno-venouS lung assisT (REST) is a randomised, allocation concealed, controlled, open, multicentre pragmatic trial to determine the clinical and cost-effectiveness of lower tidal volume mechanical ventilation facilitated by vv-ECCO₂R in patients with acute hypoxaemic respiratory failure. Patients requiring intubation and mechanical ventilation for acute hypoxaemic respiratory failure will be randomly allocated to receive either vv-ECCO₂R and lower tidal volume mechanical ventilation or standard care with stratification by recruitment centre. There is a need for a large randomised controlled trial to establish whether vv-ECCO₂R in acute hypoxaemic respiratory failure can allow the use of a more protective lung ventilation strategy and is associated with improved patient outcomes.

Reducing chest injuries in automobile collisions: rib fracture timing and implications for thoracic injury criteria

The purpose of this study was to quantify the biomechanical response of the human thorax during dynamic shoulder belt loading representative of that seen in a severe automotive collision. Two post-mortem human surrogates (PMHSs) (one male and one female) were instrumented with 26 single-axis strain gages on the ribs, sternum, and clavicle. The thorax of each PMHS was placed on a custom spine support bracket designed to support the thorax on either side of the spinous process, thereby allowing free motion at the costovertebral joints. In addition, the support bracket raised the thorax above the flat base plate, which could otherwise constrain the deformation and motion of the posterior region of the rib cage. The thorax of each PMHS was then loaded using a custom table-top belt loading system that generated thoracic displacement rates representative of a severe automotive collision, 1.3 m/s for the male PMHS and 1.0 m/s for the female PMHS. The rib fracture timing data, determined by analyzing the strain gage time histories, showed that severe thoracic injury (AIS = 3) occurred at 16% chest compression for the male and 12% chest compression for the female. However, these values are well below the current thoracic injury criteria of 29% chest compression for the male and 23% chest compression for the female. This data illustrates that serious thoracic injury (AIS = 3) occurs at lower chest compressions than the current ATD thoracic injury criteria. Overall, this study provides critical data that can be used in the design and validation of advanced ATDs and finite element models, as well as the establishment of improved, more stringent thoracic injury criteria.

Rib fracture timing in dynamic belt tests with human cadavers

The purpose of this article is to present data from dynamic belt loading tests on the thorax of human cadavers where the exact timing of all rib fractures is known. To quantify rib fracture timing, a total of 47 strain gages were placed throughout the thorax of two human cadavers (one male, one female). To simulate thoracic loading observed in a severe car crash, a custom table-top belt loading device was developed. The belt loading pulse was configured to result in approximately 40% chest compression during a 150 ms load and unload cycle. The time histories of each strain gage were analyzed to determine the time of each rib fracture which was then directly compared with the reaction loads and chest displacements at that exact time, thereby creating a noncensored data set. In both cadavers, all rib fractures occurred within the first 35% compression of the thorax. As a general trend, fractures on the left side of the thorax, where the passenger belt passed over the abdomen, occurred first followed by fractures to the upper ribs on the right side of the thorax. By utilizing this technique, the exact timing of each injury level can be characterized relative to the mechanical parameters. For example, using rib fractures as the parameter for Abbreviated Injury Scale (AIS) scores in the female test, it was shown that AIS 1 injury occurred at a chest compression of 21.1%, AIS 2 at 21.6%, AIS 3 at 22.0%, and AIS 4 at 33.3%.

Prevalence of vitamin D inadequacy in Belfast following fragility fracture

BACKGROUND

It is well established that vitamin D levels are sub-optimal in older people and that adults with fragility fracture have low levels of serum vitamin D.

OBJECTIVES

To investigate the prevalence of vitamin D inadequacy in an elderly population with fragility fractures and to compare data with previously published work from Glasgow.

RESEARCH DESIGN AND METHODS

Two retrospective patient audits were carried out using records from the out-patient Osteoporosis Clinic at Musgrave Park Hospital and from in-patient hip fracture admissions at the Royal Victoria Hospital.

RESULTS

There were data for 86 patients with fragility fracture from the Osteoporosis Clinic, 40.7% patients had vertebral fractures and 10.5% multiple fractures. Patients with hip fracture were excluded from the analysis. 69.8% of the patients were women. The mean age at the time of fracture was 65.3 years and 70.9% of patients were aged 60 years or over and 32.6% were aged 75 years or over. At the time of out-patient attendance, 73.3% were receiving supplementation with calcium and vitamin D. The mean vitamin D level was 52.3 nmol/L (21.0 ng/mL), SD = 23.4 (9.4). There were 83.7% of patients who had a vitamin D level < 80 nmol/L, 73.3% < 70 nmol/L and 55.8% < 50 nmol/L. There were no significant differences by patient age or sex. Data were also analysed according to supplementation status, in patients not taking supplements (n = 23) mean vitamin D level was 48.1 nmol/L (19.3 ng/mL), SD = 27.4 (11.0) compared with 53.8 nmol/L (21.6 ng/mL), SD = 21.8 (8.7) in the 63 patients taking supplements. Prevalence of inadequacy was higher in the patients not taking supplements 82.6% versus 67.1% at the 70 nmol/L threshold. There were data for 43 hip fracture patients, 95.3% of the patients were women. The mean age at the time of fracture was 78.3 years, 95.3% of patients were aged 60 years or over and 69.8% were aged 75 years or over. Data were not available on whether these patients were receiving supplementation. The mean vitamin D level was 36.1 nmol/L (14.5 ng/mL), SD = 24.8 (9.9). 90.7% of patients had a vitamin D level < 80 nmol/L, 88.4% < 70 nmol/L ( approximately 28 ng/mL) and 88.4% < 50 nmol/L ( approximately 20 ng/mL).

CONCLUSIONS

The levels of vitamin D inadequacy revealed in this audit were similar to those in an earlier audit carried out in Glasgow. Thus studies at two locations in the UK confirm the high prevalence of vitamin D inadequacy, furthermore, the prevalence of inadequacy appears to be higher in those patients with a hip fracture.

A study of bone mineral density in women with forearm fracture in Northern Ireland

A group of Northern Ireland women aged 40-75 years of age with low-trauma forearm fracture were studied to determine the incidence of such fractures and the prevalence of osteoporosis in this fracture population. A total of 1,147 subjects were identified in 1997 and 1998 throughout Northern Ireland following low-trauma forearm fractures, as well as 699 residents in the Eastern Health and Social Services Board (EHSSB), enabling calculation of the annual incidence rate of new low-trauma forearm fractures at 2.69/1,000 population aged 40-75. A total of 375 participants consented to have bone mineral density (BMD) measurements undertaken at the femoral neck, spine, and forearm using a Lunar Expert bone densitometer. Osteoporosis at the femur was present in 14% of women, at the spine in 29%, and at the forearm in 32%. A total of 45% were osteoporotic at one or more measured sites, but only 18% were on treatment for osteoporosis. Additional significant risk factors identified included an early menopause in 24.5% and current or previous corticosteroid use in 13%. Only 1.6% received information on treatment of osteoporosis at the time of fracture. Increased awareness is needed in both primary and secondary care including fracture services to improve treatment of women with low-trauma fracture.

Characterization of the Interactions of Estrogen Receptor and MNAR in the Activation of cSrc

In this study, we have evaluated the molecular mechanism of Src activation after its interaction with estrogen receptor α (ERα) and a newly identified scaffold protein, called MNAR (modulator of nongenomic activity of ER). Under basal condition, Src enzymatic activity is inhibited by intramolecular interactions. The enzyme can be activated by interaction between the SH2 domain of Src and phosphotyrosine-containing sequences and/or by interaction between the SH3 domain of Src and proteins containing PXXP motifs. Mutational analysis and functional evaluation of MNAR and the use of ERα and cSrc mutants revealed that MNAR interacts with Src’s SH3 domain via its N-terminal PXXP motif. Mutation of this motif abolished both the MNAR-induced activation of Src and the stimulation of ER transcriptional activity. ER interacts with Src’s SH2 domain using phosphotyrosine 537, and this complex was further stabilized by MNAR-ER interaction. Mapping studies reveal that both the A/B domain and Y537 of ERα are required for MNAR-induced activation of ER transcriptional activity. The region responsible for MNAR interaction with ER maps to two N-terminal LXXLL motifs of MNAR. Mutation of these motifs prevented ER-MNAR complex formation and eliminated activation of the Src/MAPK pathway. These data explicate how the coordinate interactions between MNAR, ER, and Src lead to Src activation. Our findings also demonstrate that MNAR is a scaffold protein that mediates ER-Src interaction and plays an important role in the integration of ER action in Src-mediated signaling.

Potential importance of Legionella species as etiologies in community acquired pneumonia (CAP)

Large percentages of patients with community acquired pneumonia (CAP) do not have a defined etiology. Between 1992-1993, 99 acute and convalescent sera were collected from patients with CAP of unknown etiology. The sera were tested using an indirect immunofluorescence antibody assay (IFA) against the following antigens: Legionella pneumophila, serogroups 3,5,6 and 7 and L. longbeachae, L. anisa, L. bozemanii and Legionella-Like Amoebal Pathogens (LLAP). A four-fold rise in titer to at least one of the antigens tested, was seen in 14% of patients; 8% to L. bozemanii, 4% to L. anisa, 2% to S. lyticum, 2% to LLAP 10 and 1% each to LLAP 1, 6 and 9. Two patients reacted to several antigens. These results indicate that other species of legionella may be important in the etiology of CAP. L. bozemanii was the organism identified in the majority of these infections. Better diagnostic studies i.e. cultures, serologies and urinary antigen testing, which recognize legionella isolates other than L. pneumophila serogroup 1 need to be developed.

Value of noninvasive studies in community-acquired pneumonia

Noninvasive diagnostic studies, i.e., sputum gram stain, sputum culture, blood culture and antigen detection assays will assist the clinician in the selection of initial antimicrobial therapy in some patients. These tests may be even more valuable in adjusting treatment regimens to prevent the use of broad spectrum antimicrobial agents as routine therapy.

Comparison of triamcinolone acetonide nasal inhaler with astemizole in the treatment of ragweed-induced allergic rhinitis

BACKGROUND

Few clinical trials have directly compared the efficacy of antihistamines with topical nasal corticosteroids.

OBJECTIVE

The study was performed to compare the efficacy and safety of triamcinolone acetonide nasal spray at a dose of 110 micro g in each nostril once daily with 10 mg of oral astemizole once daily for the treatment of seasonal allergic rhinitis.

METHODS

A multicenter, double-blind, parallel-group study was conducted in 239 patients who were randomized to receive either triamcinolone acetonide or astemizole. A 5-day, drug-free, lead-in period was followed by 4 weeks of double-blind treatment. One hundred four patients treated with triamcinolone acetonide and 105 patients treated with astemizole could be evaluated.

RESULTS

Overall, triamcinolone acetonide was more effective than astemizole in reducing total nasal symptoms, nasal stuffiness, nasal itching, and sneezing (p </= 0.01). Triamcinolone acetonide was superior to astemizole at weeks 1, 2, and 3 in reduction of the total nasal symptom score (p </= 0.0401) and in reduction of nasal stuffiness (p </= 0.05). Improvements in individual nasal symptoms (itching, postnasal drip, runny nose, and sneezing) were greater for triamcinolone acetonide at week 2 (p </= 0.01). Ocular symptoms improved from baseline in both groups. When pollen counts were correlated to mean nasal rhinitis scores, the triamcinolone acetonide group showed continued improvement from week 1 to week 2 in nasal symptoms when pollen counts were at their highest. During the same period, patients treated with astemizole failed to show improvement from week 1 to week 2. This study demonstrated that once daily administration of triamcinolone acetonide was more effective than astemizole for controlling nasal symptoms of seasonal allergic rhinitis, especially during the peak pollination period.

Efficacious response with lower dose indapamide therapy in the treatment of elderly patients with mild to moderate hypertension

A low dose (1.25 mg) of indapamide (Lozol, Rhône-Poulenc Rorer Pharmaceuticals, Collegeville, PA) was evaluated in 222 elderly patients (> or = 50 years) with mild to moderate essential hypertension in a multicenter, randomized, double-blind, parallel-group clinical trial. A 4-week single-blind placebo washout period was followed by an 8-week double-blind treatment period. Patients were randomized to receive indapamide 1.25 mg/day or to receive placebo. The primary efficacy variable was the mean change in sitting diastolic blood pressure from baseline to week 8. Eighty-one patients in the indapamide group (73%) and 87 patients in the placebo group (78%) completed the 8 weeks of double-blind therapy. Therapy with 1.25 mg of indapamide produced greater reductions compared with placebo in sitting diastolic blood pressure after 8 weeks of therapy, with statistical significance (P < or = 0.0015) seen after only 2 weeks of therapy and continuing throughout the 8 weeks. All secondary efficacy measures (sitting systolic blood pressure, standing systolic and diastolic blood pressures, and > or = 10 mm Hg decrease or final value of < or = 90 mm Hg in sitting diastolic blood pressure) also showed superior (P < or = 0.0014) improvement in the indapamide group compared with placebo after 8 weeks of double-blind treatment. During the 8-week double-blind treatment period, incidence rates for all adverse events and for drug-related adverse events were similar between the two treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood pressure control with diltiazem XR, a novel extended-release formulation of diltiazem HCl, in mature and elderly hypertensive patients

The safety and efficacy of an extended-release form of diltiazem HCl (diltiazem XR) in patients 55 years or older with mild-to-moderate essential hypertension were examined in a multi-center, double-blind, randomized, placebo-controlled, parallel-group study involving 350 patients with supine diastolic blood pressure (DBP) between 95 mm Hg and 114 mm Hg. Patients were randomized to a once-daily dose of diltiazem XR (240 mg) or placebo; 261 patients received diltiazem XR and 89 received placebo. After 4 weeks, the dose was doubled (to 480 mg) in patients whose supine DBP was > 90 mm Hg, and treatment was continued for another 4 weeks. Diltiazem XR consistently reduced blood pressure (BP) in the study population. At end-point, the mean reduction in supine DBP was 8.65 mm Hg in the diltiazem XR group and 2.75 mm Hg in the placebo group (P < 0.0001). Subgroup analysis confirmed the efficacy of diltiazem XR in men, women, patients between the ages of 55 and 64 years, patients 65 years or older, and non-black patients. Other BP values (supine systolic, standing diastolic, and standing systolic) also were significantly reduced in patients treated with diltiazem XR. BP reduction (supine DBP < or = 90 mm Hg or by > or = 10 mm Hg) was achieved in 58% of patients receiving diltiazem XR compared with 27% of patients receiving placebo. Decreases in apical heart rate were minimal and similar in both groups. No significant differences were noted in adverse events in the diltiazem XR and placebo groups: 36.4% of patients in the diltiazem XR group and 37.1% in the placebo group had no adverse experiences, and 63.6% and 62.9%, respectively, had at least one adverse event. Physical examination findings and laboratory values were clinically unremarkable and comparable in the diltiazem XR and placebo groups. Diltiazem XR given once daily at doses of 240 mg and 480 mg was safe and effective in lowering blood pressure in mature and elderly patients with mild-to-moderate hypertension.

Prior feeding alters the response to the 50-g glucose challenge test in pregnancy. The Staub-Traugott effect revisited

OBJECTIVE

To examine the effect of prior meal ingestion on the glucose, insulin, and C-peptide response to a 50-g glucose challenge test in the third trimester of pregnancy.

RESEARCH DESIGN AND METHODS

Ten pregnant women with gestational diabetes mellitus and 12 nondiabetic pregnant control subjects matched for age and weight underwent a 50-g glucose challenge test on three occasions within a 2-wk period, in random order. On one occasion the test was administered in the fasting state (fasting glucose challenge test), on a second occasion the test was administered 1 h after ingestion of a standard mixed meal (1-h postprandial study), and on a third occasion the test was administered 2 h after ingestion of a standard mixed meal (2-h postprandial study).

RESULTS

In the control subjects, the plasma glucose level 1 h after ingestion of 50 g of glucose was higher in the fasting study (7.8 +/- 0.4 mM, 7 of 12 subjects with glucose > or = 7.8 mM) than in the 1-h postprandial study (6.7 +/- 0.3 mM, 3 of 12 subjects with glucose > or = 7.8 mM) and the 2-h postprandial study of (6.3 +/- 0.4 mM, 3 of 12 with glucose > or = 7.8 mM) (P < 0.01). In the postprandial studies of control subjects, insulin and C-peptide levels were higher at the time of ingestion of the 50 g of glucose, but the early (1 h) insulin secretory response was less than in the fasting study. In the diabetic patients, glucose levels 1 h after 50-g glucose ingestion were similar in the fasting study (10.5 +/- 0.4 mM, no subjects with glucose value < 7.8 mM) and the 1-h postprandial study (11.0 +/- 0.6 mM, 1 subject with glucose < 7.8 mM), but was lower in the 2-h postprandial study (9.3 +/- 0.3 mM, 1 subject with glucose < 7.8 mM) (P < 0.03). In contrast to the control subjects, the insulin secretory response to 50 g of oral glucose was greater in the two postprandial studies than in the fasting study.

CONCLUSIONS

We have reached the following conclusions. 1) In nondiabetic gravidas, plasma glucose concentrations 1 h after ingestion of a 50-g oral glucose load are higher if administered in the fasting state compared with the postprandial state. 2) During normal pregnancy the Staub-Traugott Effect, i.e., improved glucose disposal after successive glucose load administrations, occurs and appears to be caused by mechanisms other than enhanced insulin secretion with successive glucose loads. 3) The effect of the prandial state on plasma glucose response to the 50-g glucose challenge test used to screen for gestational diabetes mellitus may be of sufficient magnitude to significantly alter the operating characteristics, i.e., sensitivity and specificity, of this test.

Multiple antibiotic resistance in Pseudomonas aeruginosa: evidence for involvement of an efflux operon

An outer membrane protein of 50 kDa (OprK) was overproduced in a siderophore-deficient mutant of Pseudomonas aeruginosa capable of growth on iron-deficient minimal medium containing 2,2'-dipyridyl (0.5 mM). The expression of OprK in the mutant (strain K385) was associated with enhanced resistance to a number of antimicrobial agents, including ciprofloxacin, nalidixic acid, tetracycline, chloramphenicol, and streptonigrin. OprK was inducible in the parent strain by growth under severe iron limitation, as provided, for example, by the addition of dipyridyl or ZnSO4 to the growth medium. The gene encoding OprK (previously identified as ORFC) forms part of an operon composed of three genes (ORFABC) implicated in the secretion of the siderophore pyoverdine. Mutants defective in ORFA, ORFB, or ORFC exhibited enhanced susceptibility to tetracycline, chloramphenicol, ciprofloxacin, streptonigrin, and dipyridyl, consistent with a role for the ORFABC operon in multiple antibiotic resistance in P. aeruginosa. Sequence analysis of ORFC (oprK) revealed that its product is homologous to a class of outer membrane proteins involved in export. Similarly, the products of ORFA and ORFB exhibit homology to previously described bacterial export proteins located in the cytoplasmic membrane. These data suggest that ORFA-ORFB-oprK (ORFC)-dependent drug efflux contributes to multiple antibiotic resistance in P. aeruginosa. We propose, therefore, the designation mexAB (multiple efflux) for ORFAB.

The interactions between nisoldipine and two beta-adrenoceptor antagonists--atenolol and propranolol

1. The interactions between the dihydropyridine calcium antagonist nisoldipine and two beta-adrenoceptor blocker drugs (atenolol and propranolol) were investigated in two groups of healthy normotensive subjects. 2. The steady state plasma concentrations of both beta-adrenoceptor blockers were significantly altered by the addition of nisoldipine: for propranolol there were significant increases in Cmax, by about 50%, and in AUC by about 30% and for atenolol there was a significant increase in Cmax, by about 20%. 3. The addition of nisoldipine was also associated with significant changes in apparent liver blood flow (measured by indocyanine green clearance) from 1.4 to 2.4 l min-1 in the atenolol group and from 1.3 to 2.3 l min-1 in the propranolol group. 4. Both nisoldipine-beta-adrenoceptor blocker combinations were associated with small enhanced blood pressure reductions e.g. from 104/60 with atenolol alone to 98/50 mm Hg with the combination but there was no alteration to the extent of beta-adrenoceptor blockade (as assessed by bicycle ergometry). 5. This pharmacodynamic profile in healthy normotensives is consistent with the known therapeutic efficacy of such combination treatments in patients with hypertension and angina. 6. It is suggested that there is a pharmacokinetic component to the efficacy of this type of combination, perhaps reflecting vasodilator-induced changes in drug absorption and/or hepatic extraction.

Professional ice hockey players: physiologic, anthropometric, and musculoskeletal characteristics

Twenty-seven players from a National Hockey League (NHL) team were evaluated for maximal aerobic power, body composition, and muscle strength and flexibility upon reporting to training camp. Aerobic power was determined with a maximal treadmill exercise test. Body composition was determined by underwater weighing. Muscle strength of the internal and external shoulder rotator muscles and the knee flexors and extensors were determined isokinetically at 30 degrees/sec. Strength of the hip adductors was determined isometrically. The average (+/- standard error) maximal oxygen consumption (VO2max) for all players was 53.4 +/- 0.8 ml x kg-1 x min-1. When players were grouped by their usual playing positions (Goalies = G, n = 4; Forwards = F, n = 15; and Defensemen = D, n = 8) there were no differences in VO2 max, resting or maximal heart rate, and exercise test duration. Although G (77.7 +/- 3.2 kg) were significantly lighter than D (88.5 +/- 1.9 kg) and F (86.1 +/- 1.9 kg), there were no significant differences between player positions in height or percentage of body fat (9.2 +/- 0.9%). Measures of absolute muscle strength and muscle strength adjusted for body weight were similar for G, F, and D. Goalies, however, had significantly more flexibility in the hip and groin musculature than F and D. Although team averages for muscle strength and flexibility were normal and symmetric, ten players (37%) exhibited significant musculoskeletal strength and flexibility deficits.

The effects of exercise and weight loss on plasma lipids in young obese men

We studied the independent and combined effects of exercise training and weight loss on blood lipids under fixed diet and exercise conditions. Twenty-one obese sedentary men were randomly allocated to one of four treatment groups: (1) inactive and constant weight (control), (2) exercise training and constant weight, (3) inactive and weight loss, and (4) exercise training and weight loss. There were three study periods: a 3 week baseline period inactive and on an isocaloric diet, a 12 week treatment period, and a 3 week weight stabilization period. Exercise consisted of treadmill walking at an energy cost of 3500 kcal/wk for groups 2 and 4 with replacement caloric intake only in group 2. Group 3 reduced caloric intake by 3500 kcal/wk during the treatment period. Weight loss for groups 3 and 4 were 13.4 pounds and 13.7 pounds, respectively. Maximal oxygen uptake (mL/min) increased 6% in both exercise groups (2 and 4), and percent body fat decreased only in these groups. Regression analysis by group assignment on HDL cholesterol (HDL-C) showed that the inactivity-weight loss modality (group 3) and the exercise-constant weight modality (group 2) each significantly increased HDL-C, with an additive effect of exercise and weight loss (group 4). The rate of HDL-C change differed significantly between groups (P = 0.01). HDL-C increased 0.63, 0.61, and 1.89 mg/dL per 3 weeks or 2%, 2.4%, and 5.5% above baseline levels in groups 2, 3, and 4, respectively, while the control group decreased 0.11 mg/dL. Plasma triglycerides and very low-density lipoprotein (VLDL) cholesterol increased with exercise at constant weight (group 2) and decreased with exercise associated with weight loss (group 4). In conclusion, exercise and weight loss separately and independently increase HDL-C, and their effects are additive.

Blood lipid effects of antihypertensive therapy: a double-blind comparison of the effects of methyldopa and propranolol

Thirty-two middle-aged men with essential hypertension completed a double-blind randomly allocated comparison of the effects of methyldopa versus propranolol on blood lipid levels. After a four-week period on a placebo for each drug, subjects were titrated for the next six weeks with either methyldopa from 500 to 2000 mg/day or propranolol from 80 to 320 mg/day plus a placebo for the other drug until supine diastolic blood pressure was below 90 mm Hg or the ceiling dose was reached. Subjects were then maintained on the achieved drug dose for an additional six weeks and finally switched back to a placebo for each drug for four more weeks. Blood lipid levels were measured twice during each study period and the values averaged and compared. Neither drug significantly affected levels of total plasma cholesterol. However, both drugs reduced high-density lipoprotein (HDL) cholesterol levels about 10 per cent and increased the total cholesterol to HDL cholesterol ratio. In addition, propranolol significantly increased plasma triglyceride levels (28.3 per cent). The changes in lipid levels were not dose related. Whether or not these blood lipid changes persist and their possible clinical implication during prolonged therapy remain to be elucidated.

Clinical assessment and follow-up of functional capacity in patients with chronic congestive cardiomyopathy

The presumption that the results of left ventricular systolic function tests performed at rest are related to the symptoms of chronic congestive heart failure or to exercise capacity is unproved. Thirty-three patients with chronic congestive cardiomyopathy underwent serial exercise tests, determinations of ejection fraction and systolic time intervals, echocardiograms, assessment of symptom score, chest roentgenogram, and physical examination over a mean ( +/- standard deviation) of 24.8 +/- 14.1 months. Maximal exercise performance achieved correlation with symptoms (r = 0.66) but not with indexes of left ventricular function. Edema, elevated jugular venous pressure, rales and radiologic evidence of pulmonary venous hypertension were more common in patients with severe limitation of exercise capacity. in 17 patients whose functional capacity changed during the follow-up period, congruent changes in left ventricular function measured at rest were not consistently observed. Thus the findings on history, physical examination and radiologic examination correlate with exercise capacity, but indexes of left ventricular performance at rest do not and therefore are of limited use in assessing treatment. The clinical course of patients with chronic congestive cardiomyopathy can be followed up safely, effectively and economically by simple clinical observations. Serial laboratory testing of left ventricular function can be reserved for specific indications, research and patients with valvular heart disease.

Cross-modal performance in patients with cerebral lesions

52 patients with circumscribed cerebral lesions, and 35 control patients (lesions in the posterior fossa or in the spinal cord), were assessed for their ability to match spatial configurations: matching was either cross-modal (visual-tactual or tactual-visual). or within-modal (visual-visual or tactual-tactual). They were also tested for cross-modal transfer (visual-tactual or tactual-visual). All materials were "easy" or "hard". Associated defects (e.g. dysphasia, apraxia) were also assessed. It was found that neither site of lesion, nor laterality of lesion, nor presence of any associated defect was significantly and selectively associated with impairment of cross-modal performance.