A Research Protocol to Study the Priming Effects of Breathing Low Oxygen on Enhancing Training-Related Gains in Walking Function for Persons With Spinal Cord Injury: The BO2ST Trial

Brief episodes of low oxygen breathing (therapeutic acute intermittent hypoxia; tAIH) may serve as an effective plasticity-promoting primer to enhance the effects of transcutaneous spinal stimulation-enhanced walking therapy (WALKtSTIM) in persons with chronic (>1 year) spinal cord injury (SCI). Pre-clinical studies in rodents with SCI show that tAIH and WALKtSTIM therapies harness complementary mechanisms of plasticity to maximize walking recovery. Here, we present a multi-site clinical trial protocol designed to examine the influence of tAIH + WALKtSTIM on walking recovery in persons with chronic SCI. We hypothesize that daily (eight sessions, 2 weeks) tAIH + WALKtSTIM will elicit faster, more persistent improvements in walking recovery than either treatment alone. To test our hypothesis, we are conducting a placebo-controlled clinical trial on 60 SCI participants who randomly receive one of three interventions: tAIH + WALKtSTIM; Placebo + WALKtSTIM; and tAIH + WALKtSHAM. Participants receive daily tAIH (fifteen 90-sec episodes at 10% O2 with 60-sec intervals at 21% O2) or daily placebo (fifteen 90-sec episodes at 21% O2 with 60-sec intervals at 21% O2) before a 45-min session of WALKtSTIM or WALKtSHAM. Our primary outcome measures assess walking speed (10-Meter Walk Test), endurance (6-Minute Walk Test), and balance (Timed Up and Go Test). For safety, we also measure pain levels, spasticity, sleep behavior, cognition, and rates of systemic hypertension and autonomic dysreflexia. Assessments occur before, during, and after sessions, as well as at 1, 4, and 8 weeks post-intervention. Results from this study extend our understanding of the functional benefits of tAIH priming by investigating its capacity to boost the neuromodulatory effects of transcutaneous spinal stimulation on restoring walking after SCI. Given that there is no known cure for SCI and no single treatment is sufficient to overcome walking deficits, there is a critical need for combinatorial treatments that accelerate and anchor walking gains in persons with lifelong SCI.

Trial Registration

ClinicalTrials.gov, NCT05563103.

The flashfm approach for fine-mapping multiple quantitative traits

Joint fine-mapping that leverages information between quantitative traits could improve accuracy and resolution over single-trait fine-mapping. Using summary statistics, flashfm (flexible and shared information fine-mapping) fine-maps signals for multiple traits, allowing for missing trait measurements and use of related individuals. In a Bayesian framework, prior model probabilities are formulated to favour model combinations that share causal variants to capitalise on information between traits. Simulation studies demonstrate that both approaches produce broadly equivalent results when traits have no shared causal variants. When traits share at least one causal variant, flashfm reduces the number of potential causal variants by 30% compared with single-trait fine-mapping. In a Ugandan cohort with 33 cardiometabolic traits, flashfm gave a 20% reduction in the total number of potential causal variants from single-trait fine-mapping. Here we show flashfm is computationally efficient and can easily be deployed across publicly available summary statistics for signals in up to six traits.

Acute intermittent hypoxia boosts spinal plasticity in humans with tetraplegia

Paired corticospinal-motoneuronal stimulation (PCMS) elicits spinal synaptic plasticity in humans with chronic incomplete cervical spinal cord injury (SCI). Here, we examined whether PCMS-induced plasticity could be potentiated by acute intermittent hypoxia (AIH), a treatment also known to induce spinal synaptic plasticity in humans with chronic incomplete cervical SCI. During PCMS, we used 180 pairs of stimuli where corticospinal volleys evoked by transcranial magnetic stimulation over the hand representation of the primary motor cortex were timed to arrive at corticospinal-motoneuronal synapses of the first dorsal interosseous (FDI) muscle ~1-2 ms before the arrival of antidromic potentials elicited in motoneurons by electrical stimulation of the ulnar nerve. During AIH, participants were exposed to brief alternating episodes of hypoxic inspired gas (1 min episodes of 9% O₂) and room air (1 min episodes of 20.9% O₂). We examined corticospinal function by measuring motor evoked potentials (MEPs) elicited by cortical and subcortical stimulation of corticospinal axons and voluntary motor output in the FDI muscle before and after 30 min of PCMS combined with AIH (PCMS+AIH) or sham AIH (PCMS+sham-AIH). The amplitude of MEPs evoked by magnetic and electrical stimulation increased after both protocols, but most after PCMS+AIH, consistent with the hypothesis that their combined effects arise from spinal plasticity. Both protocols increased electromyographic activity in the FDI muscle to a similar extent. Thus, PCMS effects on spinal synapses of hand motoneurons can be potentiated by AIH. The possibility of different thresholds for physiological vs behavioral gains needs to be considered during combinatorial treatments.

Effect of acute intermittent hypoxia on motor function in individuals with chronic spinal cord injury following ibuprofen pretreatment: A pilot study

INTRODUCTION

Acute intermittent hypoxia (AIH) enhances lower extremity motor function in humans with chronic incomplete spinal cord injury (SCI). AIH-induced spinal plasticity is inhibited by systemic inflammation in animal models. Since SCI is frequently associated with systemic inflammation in humans, we tested the hypothesis that pretreatment with the anti-inflammatory agent ibuprofen enhances the effects of AIH.

METHODS

A randomized, double-blinded, placebo-controlled crossover design was used. Nine adults (mean age 51.1 ± 13.1 years) with chronic motor-incomplete SCI (7.7 ± 6.3 years post-injury) received a single dose of ibuprofen (800 mg) or placebo, 90 minutes prior to AIH. For AIH, 9% O₂ for 90 seconds was interspersed with 21% O₂ for 60 seconds. Maximal voluntary ankle plantar flexion isometric torque was assessed prior to, and at 0, 30, and 60 minutes post-AIH. Surface electromyography (EMG) of plantar flexor muscles was also recorded.

RESULTS

Torque increased significantly after AIH at 30 (P = 0.007; by ∼20%) and 60 (P < 0.001; by ∼30%) minutes post-AIH versus baseline. Ibuprofen did not augment the effects of AIH. EMG activity did not increase significantly after AIH; however, there was a significant association between increases in torque and EMG in both gastrocnemius (R² = 0.17, P < 0.005) and soleus (R² = 0.17, P < 0.005) muscles.

CONCLUSIONS

AIH systematically increased lower extremity torque in individuals with chronic incomplete SCI, but there was no significant effect of ibuprofen pretreatment. Our study re-confirms the ability of AIH to enhance leg strength in persons with chronic incomplete SCI.

Collaborative meta-analysis of individual participant data from observational studies of Lp-PLA2 and cardiovascular diseases

BACKGROUND

A large number of observational epidemiological studies have reported generally positive associations between circulating mass and activity levels of lipoprotein-associated phospholipase A2 (Lp-PLA2) and the risk of cardiovascular diseases. Few studies have been large enough to provide reliable estimates in different circumstances, such as in different subgroups (e.g., by age group, sex, or smoking status) or at different Lp-PLA2 levels. Moreover, most published studies have related disease risk only to baseline values of Lp-PLA2 markers (which can lead to substantial underestimation of any risk relationships because of within-person variability over time) and have used different approaches to adjustment for possible confounding factors.

OBJECTIVES

By combination of data from individual participants from all relevant observational studies in a systematic 'meta-analysis', with correction for regression dilution (using available data on serial measurements of Lp-PLA2), the Lp-PLA2 Studies Collaboration will aim to characterize more precisely than has previously been possible the strength and shape of the age and sex-specific associations of plasma Lp-PLA2 with coronary heart disease (and, where data are sufficient, with other vascular diseases, such as ischaemic stroke). It will also help to determine to what extent such associations are independent of possible confounding factors and to explore potential sources of heterogeneity among studies, such as those related to assay methods and study design. It is anticipated that the present collaboration will serve as a framework to investigate related questions on Lp-PLA2 and cardiovascular outcomes.

METHODS

A central database is being established containing data on circulating Lp-PLA2 values, sex and other potential confounding factors, age at baseline Lp-PLA2 measurement, age at event or at last follow-up, major vascular morbidity and cause-specific mortality. Information about any repeat measurements of Lp-PLA2 and potential confounding factors has been sought to allow adjustment for possible confounding and correction for regression dilution. The analyses will involve age-specific regression models. Synthesis of the available observational studies of Lp-PLA2 will yield information on a total of about 15 000 cardiovascular disease endpoints.

Targeting HER3 by interfering with its Sec61-mediated cotranslational insertion into the endoplasmic reticulum

There is increasing evidence implicating HER3 in several types of cancer. But the development of targeted therapies to inactivate HER3 function has been a challenging endeavor. Its kinase domain functions in allostery not catalysis, and the classical ATP-analog class of tyrosine kinase inhibitors fail to inactivate it. Here we describe a novel approach that eliminates HER3 expression. The small-molecule cotransin CT8 binds the Sec61 translocon and prevents the signal peptide of the nascent HER3 protein from initiating its cotranslational translocation, resulting in the degradation of HER3 but not the other HER proteins. CT8 treatment suppresses the induction of HER3 that accompanies lapatinib treatment of HER2-amplified cancers and synergistically enhances the apoptotic effects of lapatinib. The target selectivities of cotransins are highly dependent on their structure and the signal sequence of targeted proteins and can be narrowed through structure-function studies. Targeting Sec61-dependent processing identifies a novel strategy to eliminate HER3 function.

Supraclavicularis proprius muscle associated with supraclavicular nerve entrapment

Entrapment neuropathy of the supraclavicular nerve is rare and, when it occurs, is usually attributable to branching of the nerve into narrow bony clavicular canals. We describe another mechanism for entrapment of this nerve with the aberrant muscle; supraclavicularis being found during the routine dissection of an embalmed 82-year-old cadaver. Our report details a unique location for this rare muscular variation whereby the muscle fibres originated posteriorly on the medial aspect of the clavicle before forming a muscular arch over the supraclavicular nerve and passing laterally towards the trapezius and acromion. We recommend that in clinical instances of otherwise unexplained unilateral clavicular pain or tenderness, nerve compression from the supraclavicularis muscle must be borne in mind.

Bayesian methods for meta-analysis of causal relationships estimated using genetic instrumental variables

Genetic markers can be used as instrumental variables, in an analogous way to randomization in a clinical trial, to estimate the causal relationship between a phenotype and an outcome variable. Our purpose is to extend the existing methods for such Mendelian randomization studies to the context of multiple genetic markers measured in multiple studies, based on the analysis of individual participant data. First, for a single genetic marker in one study, we show that the usual ratio of coefficients approach can be reformulated as a regression with heterogeneous error in the explanatory variable. This can be implemented using a Bayesian approach, which is next extended to include multiple genetic markers. We then propose a hierarchical model for undertaking a meta-analysis of multiple studies, in which it is not necessary that the same genetic markers are measured in each study. This provides an overall estimate of the causal relationship between the phenotype and the outcome, and an assessment of its heterogeneity across studies. As an example, we estimate the causal relationship of blood concentrations of C-reactive protein on fibrinogen levels using data from 11 studies. These methods provide a flexible framework for efficient estimation of causal relationships derived from multiple studies. Issues discussed include weak instrument bias, analysis of binary outcome data such as disease risk, missing genetic data, and the use of haplotypes.

Autoimmune hypothyroidism protects against breast cancer development in the elderly

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Background: An association between breast cancer and autoimmune hypothyroidism has been suggested. While a biological role for thyroid hormone in breast tumorigenesis has been demonstrated in vitro, epidemiological evidence is lacking. Methods: A retrospective, population-based cohort study was conducted to examine the risk of postmenopausal breast cancer (BRCA) in women with or without autoimmune hypothyroidism, identified on the basis of prescriptions for levothyroxine (LT4). Administrative health records were used to capture information on all women aged 66 and older living in Ontario, Canada at baseline (April 1, 1993 to March 31, 1996) and during a 10-year follow up. Propensity scores were used to create a matched cohort of LT4 and non-LT4 users. Cox proportional hazards modeling was used to evaluate the impact of LT4 use on the 5-year incidence of BRCA and benign breast disease, and on all-cause mortality rates among women diagnosed with breast cancer during follow-up. Results: LT4 users (N=89,093) and non-LT4 users (N=89,093) were well-matched with respect to baseline sociodemographics, estrogen use, comorbidity, and health care utilization, including the likelihood of receiving mammography or a breast biopsy. The 5-year incidence of BRCA was 0.86% in LT4 users compared to 0.97% in non-LT4 users (p=0.002). Adjustment for baseline characteristics did not alter these results (hazard ratio [HR] 0.86; 95% confidence interval [CI] 0.77–0.95; p= 0.004). Among women who developed BRCA, all cause mortality was significantly lower in LT4 users than in non-users (43.9% vs. 56.1%; adjusted HR 0.82; 95% CI 0.70–0.96; p= 0.01). The incidence of benign breast disease did not vary between groups. Conclusions: Elderly women with autoimmune hypothyroidism appeared to have a protective advantage in the incidence of BRCA and in mortality following a breast cancer diagnosis. These results suggest a biological role for thyroid hormone in the development of breast cancer, with a modulating effect of treated autoimmune hypothyroidism in promoting a less aggressive disease course. Further studies exploring the effect of thyroid hormone in breast cancer development are needed and may uncover novel therapeutic targets in the management of breast cancer in the future.

No significant financial relationships to disclose.

Role of duplex Doppler and power Doppler sonography in transplanted kidneys with acute renal parenchymal dysfunction

The limited work published on the comparison of power Doppler sonography (PDS) and duplex Doppler sonography (DDS) in the assessment of acute renal allograft dysfunction has shown contradictory results. We compared the role of DDS and PDS in renal transplant recipients developing acute renal parenchymal dysfunction and correlated these findings with kidney biopsy, which was taken as the gold standard. Thirty post-renal transplant patients with acute graft dysfunction underwent Doppler sonography, DDS and PDS using an HDI 5000 ATL machine. Patients who developed graft dysfunction as a result of vascular, obstructive or other non-parenchymal causes were excluded. All patients underwent an allograft biopsy within 72 h of the sonography. Based on the biopsy findings, 24 patients were categorized as having acute rejection, and six patients as having no rejection. The overall sensitivity, specificity and accuracy of DDS for evaluation of graft dysfunction were 54.17, 33.33, and 50.00%, respectively, and that for PDS were superior with 87.50, 33.30, and 76.67%, respectively. The low specificity can be partially attributed to the small number of cases without rejection in our study population. We conclude that PDS is superior to DDS in screening patients with acute parenchymal renal dysfunction post-transplant. However, a normal PDS examination does not exclude the presence of acute rejection. Power Doppler sonography is a useful screening test for diagnosing acute rejection but a renal allograft biopsy remains the gold standard for diagnosis of this condition.

Twenty-year comparison of tissue and mechanical valve replacement

OBJECTIVE

We sought to compare outcomes with tissue and St Jude Medical mechanical valves over a 20-year period.

METHODS

Valve-related events and overall survival were analyzed in 2533 patients 18 years of age or older undergoing initial aortic, mitral, or combined aortic and mitral (double) valve replacement with a tissue valve (Hancock, Carpentier-Edwards porcine, or Carpentier-Edwards pericardial) or a St Jude Medical mechanical valve. Total follow-up was 13,390 patient-years. There were 666 St Jude Medical aortic valve replacements, 723 tissue aortic valve replacements, 513 St Jude Medical mitral valve replacements, 402 tissue mitral valve replacements, 161 St Jude Medical double valve replacements, and 68 tissue double valve replacements. The mean age was 68 +/- 13.3 years (St Jude Medical valve, 64.5 +/- 12.9; tissue valve, 72.0 +/- 12.6).

RESULTS

There were no overall differences in survival between tissue and mechanical valves. Multivariable analysis indicated that the type of valve did not affect survival. Analysis by age less than 65 years or 65 years or older and presence or absence of coronary disease revealed similar long-term survival in all subgroups. The risk of hemorrhage was lower in patients receiving tissue aortic valve replacements but was not significantly different in patients receiving mitral valve or double valve replacements. Thromboembolism rates were similar for tissue and mechanical valve recipients. However, reoperation rates were significantly higher in patients receiving both aortic and mitral tissue valves. The reoperation hazard increased progressively with time both in patients receiving aortic and in those receiving mitral tissue valves. Overall valve complications were initially higher with mechanical aortic valves but not with mechanical mitral valves. However, valve complication rates later crossed over, with higher rates in tissue valve recipients after 7 years in patients undergoing mitral valve replacement and 10 years in those undergoing aortic valve replacement.

CONCLUSIONS

Tissue and mechanical valve recipients have similar survival over 20 years of follow-up. The primary tradeoff is an increased risk of hemorrhage in patients receiving mechanical aortic valve replacements and an increased risk of late reoperation in all patients receiving tissue valve replacements. The risk of tissue valve reoperation increases progressively with time.

Heart transplantation in patients seventy years of age and older: A comparative analysis of outcome

OBJECTIVE

Advanced age has traditionally been considered a contraindication for heart transplantation because of the reported adverse effect of increased age on long-term survival. However, as the field of transplantation continues to evolve, the criteria regarding the recipient's upper age limit have been expanded and older patients are being considered as potential candidates. We analyzed the outcome of heart transplantation in patients 70 years of age and older and compared these results with those in younger patients (<70 years) over a 4-year period.

METHOD

We retrospectively analyzed the results of 15 patients 70 years of age and older who underwent heart transplantation between November 1994 and May 1999 and compared them with results in 98 younger patients undergoing transplantation during the same period

RESULTS

The older age group had a higher preoperative left ventricular ejection fraction (P =.02), higher incidence of female donors (P =.02), and longer cardiac allograft ischemic time (P =.01). No differences were found regarding incidence of diabetes mellitus, donor age, donor/recipient weight ratio, and mismatch (<0.80). The 30-day or to-discharge operative mortality was similar in both groups (0% in the older vs 5.1% in younger patients). Actuarial survival at 1 year and 4 years was not statistically different between the older and younger patients (93.3% +/- 6.4% vs 88.3% +/- 3.3% and 73.5% +/- 13.6% vs 69.1% +/- 5.8%, respectively). The length of intensive care unit stay and total post-transplantation hospital stay, incidence of rejection, and incidence of cytomegalovirus infection were similar between the groups.

CONCLUSIONS

Heart transplantation in selected patients 70 years of age and older can be performed as successfully as in younger patients (<70 years of age) with similar morbidity, mortality, and intermediate-term survival. Advanced age as defined (> or =70 years) should not be an exclusion criterion for heart transplantation. The risks and benefits of transplant surgery should be applied individually in a selective fashion.

Can peer-comparison feedback improve patient functional status?

OBJECTIVE

To determine whether providing physicians with peer-comparison feedback can improve patient functional status.

STUDY DESIGN

Randomized, controlled, comparative study.

METHODS

Forty-eight primary care physicians at Kaiser Permanente Woodland Hills, a group-model health maintenance organization in southern California, were randomly assigned to an intervention group or a control group. All physicians were informed that their elderly patients (randomly selected patients aged 65 to 75) would be monitored. Physicians in the intervention group received aggregated peer-comparison feedback data (physician "report cards") on the functional status of their elderly patients. Physicians in the control group received only general information that their patients' functional status would be monitored. The effect of the intervention on patients' functional status was determined by comparing responses to surveys completed by the patients at baseline and after the intervention.

RESULTS

Patients in both the control and intervention groups had a statistically significant decrease in functional status, including decreases in their ability to complete daily activities and increases in pain. In addition, patients in the control group reported a significant decrease in social activities, physical fitness, and feelings. In the intervention group, patients also experienced a significant decrease in social support.

CONCLUSIONS

Educational interventions, including peer-comparison feedback, did not result in improvements in patient functional status. Research is desperately needed to identify interventions that can lead to improved health for elderly patients.

Physician education and report cards: do they make the grade? results from a randomized controlled trial

PURPOSE

We sought to determine whether tailored educational interventions call improve the quality of care, as measured by the provision of preventive care services recommended by the US Preventive Services Task Force, as well as lead to better patient satisfaction.

SUBJECT AND METHODS

We performed a randomized controlled study among 41 primary care physicians who cared for 1,810 randomly selected patients aged 65 to 75 years old at Kaiser Permanente Woodland Hills, a group-model health maintenance organization in southern California. All physicians received ongoing education. Physicians randomly assigned to the comprehensive intervention group also received peer-comparison feedback and academic detailing. Baseline and postintervention (2 to 2.5 years later) surveys examining the provision of preventive care and patient satisfaction were performed and medical records were reviewed.

RESULTS

Based on the results of patient surveys, there were significant improvements over time in the provision of preventive care in both the education and the comprehensive intervention groups for influenza immunization (79% versus 89%, P <0.01, and 80% versus 91%, P <0.01), pneumococcal immunization (42% versus 73%, P < 0.01 and 34% versus 73%, P < 0.01), and tetanus immunization (64% versus 72%, P <0.01, and 59% versus 79%, P <0.01). Mammography (90% versus 80%, P <0.01) and clinical breast examination (85% versus 79%, P <0.05) scores worsened in the education only group but not in the comprehensive intervention group. However, there were few differences in rates of preventive services between the groups at the end of the study, and the improvements in preventive care were not confirmed by medical record review. Patient satisfaction scores improved significantly in the comprehensive intervention group (by 0.06 points on a 1 to 5 scale, P = 0.02) but not in the education only group (by 0.02 points, P = 0.42); however, the improvement was not significantly greater in the comprehensive intervention group (P = 0.20).

CONCLUSION

A physician-targeted approach of education, peer-comparison feedback, and academic detailing has modest effects on patient satisfaction and possibly on the offering of selected preventive care services. The lack of agreement between patient reports and medical records review raises concerns about current methods of ascertaining compliance with guidelines for preventive care.

Actual failure rates: A method of assessing tissue valve reoperation rates

BACKGROUND

Patients older than age 70 with coronary disease undergoing mitral valve replacement have a limited survival rate, suggesting that few of these patients will require reoperation if they receive a tissue mitral valve. However, traditional actuarial analysis of valve durability censors patients who die before valve failure and doesn't reflect the lower frequency of reoperation in patient subgroups with limited survival rates.

METHODS

Actual or cumulative reoperation rates represent the rates of reoperation in patients without censoring for death and estimate the risk that the valve will fail before the patient dies. The actual rates of valve rereplacement were determined in 255 recipients of tissue mitral valves, categorizing patients by age and presence of coronary artery disease at 8 years after surgery and compared with standard actuarial estimates of valve durability.

RESULTS

Operative mortality rates were 17.5% for patients with coronary artery disease and 6.0% for those without (P <.001). At 8 years, the actual reoperation rates for patients younger than age 70 with and without coronary artery disease were 9.2% (n = 76) and 10% (n = 90), respectively. In patients older than age 70 without coronary artery disease the reoperation rate was 9.4% (n = 32). In contrast, the actual reoperation rate was only 1.7% (n = 58) in patients older than age 70 with coronary artery disease. This rate was significantly lower (P =.05) than the other groups. The difference in reoperation rates was not significant if standard actuarial analysis was used.

CONCLUSIONS

Actual reoperation rates are significantly lower in patients older than 70 years with CAD receiving mitral tissue valves than in younger patients or in patients without coronary artery disease. Calculation of actual reoperation rates provides a unique and clinically useful perspective in evaluating data on prosthetic valve reoperation rates.

Cardiac reoperations in octogenarians: analysis of outcomes

BACKGROUND

With the rapid growth of the elderly segment of the population, more octogenarians are referred for complex cardiac interventions, including reoperations. Data regarding the outcomes, quality of life, and long-term results after reoperative open-heart surgical procedures in octogenarians are scarce.

METHODS

We retrospectively studied 113 consecutive octogenarians (mean age, 83+/-2.6 years) who underwent reoperative cardiac procedures within a 13-year period. Coronary artery bypass grafting (CABG) was performed in 49 patients (CABG group), valvular procedures (aortic, mitral, or tricuspid valve, alone or in combination) in 35 (valve group), and combined CABG and valve intervention in 29 (combined CABG and valve group).

RESULTS

The 30-day mortality rate was 8% (4 of 49) for the CABG group, 9% (3 of 35) for the valve group, and 17% (5 of 29) for the combined CABG and valve group. One- and 5-year actuarial survival rates were, respectively, 85%+/-5% and 58%+/-10% for the CABG group, 78%+/-7% and 53%+/-12% for the valve group, and 69%+/-9% and 63%+/-10% for the combined CABG and valve group. Sixty-one percent of patients in the CABG group, 40% in the valve group, and 38% in the combined CABG and valve group were in New York Heart Association class I or II postoperatively at a mean follow-up time of 2.1+/-2.4 years. Similarly, 91%, 85%, and 80%, respectively, thought that they had an improved quality of life and were satisfied with their functional status.

CONCLUSIONS

Cardiac reoperations can be performed successfully in most octogenarians, although with an increased risk, particularly in the combined CABG and valve group. Long-term survival is acceptable with improved quality of life and functional status. However, it is possible that these results could be improved in this high-risk group of patients with earlier referral and surgical intervention, for the effective use of health care resources.

A prospective, multicenter study of a pneumonia practice guideline

OBJECTIVE

To study the effect of a length of stay practice guideline on patient outcomes.

DESIGN

A prospective, nonrandomized, interventional trial.

SETTING

Six geographically distributed hospitals.

PATIENTS

Two hundred forty-two consecutively hospitalized "low-risk" patients with pneumonia.

MEASUREMENTS AND RESULTS

One hundred fifty-two patients (63%) completed the mailed postdischarge survey and were included in the analysis. Data were prospectively collected for 85 patients from the baseline observation period (B) and 67 patients from the intervention period (I). During the I, case managers provided physicians with patient risk information based on guideline recommendations. There was no significant change in guideline compliance (B vs I: 76.5% vs 83.6%; p=0.32) or length of stay (B vs I: 3.5 days [95% confidence interval, 3.2 to 3.8] vs 3.6 days [95% confidence interval, 3.3 to 4.0]). Also, there were no statistically significant effects of the intervention on patient outcomes, care following hospital discharge, and patient satisfaction scores.

CONCLUSION

Patients in this study often had shorter lengths of stay than recommended by the practice guideline. This suggests that the external environment may have had a greater effect on physician behavior and length of stay than the practice guideline itself. Moreover, it demonstrates the importance of continuous assessment of physician practices immediately prior to, during, and after application of the clinical practice guideline.

Can practice guidelines safely reduce hospital length of stay? Results from a multicenter interventional study

BACKGROUND

Although practice guidelines about appropriate lengths of stay have been widely promulgated, their effects on patient outcomes are not clear. Our objective was to study the effects of length of stay practice guidelines on patient outcomes.

PATIENTS AND METHODS

We performed a prospective, nonrandomized, interventional trial in six geographically distributed hospitals, among consecutively hospitalized "low-risk" patients with total hip replacement, hip fracture, or knee replacement. Case managers provided physicians with patient risk information based on guideline recommendations. We measured length of stay, compliance with recommended guideline length of stay, health status, hospital readmission rates, return to emergency department, return to work and recreation, and patient satisfaction.

RESULTS

A total of 560 patients were included in the study. For patients with knee replacement, there was a statistically significant increase in practice guideline compliance (27% baseline versus 53% intervention, P <0.0001) and reduction in length of stay (5.2 days versus 4.6 days, P <0.001) when compared with the baseline period. For hip replacement patients, there similarly was an increase in practice guideline compliance (66% baseline versus 82% intervention, P = 0.01) and reduction in length of stay (5.1 days versus 4.8 days, P = 0.03). Significant reductions in length of stay were not observed for patients recovering after hip fracture despite a significant increase in guideline compliance. There were few statistically significant changes in patient outcomes related to reductions in lengths of stay, including health status, hospital readmission rates, return to emergency department, return to work and recreation, and patient satisfaction. For patients undergoing hip replacement, very short lengths of stay (shorter than the guideline recommendation) were associated with an increased rate of discharging patients to nursing homes and rehabilitation facilities (21% versus 7%, P = 0.01), and hip fracture patients with very short lengths of stay required more visits to the doctor after discharge (56% versus 25%, P = 0.04).

CONCLUSION

Reductions in lengths of stay were most often associated with no significant change in patient outcomes. However, very short lengths of stay were associated with increased intensity of care following discharge for patients undergoing hip surgery, indicating possible cost shifting (the cost incurred by transferring patients to rehabilitation facilities may have been greater than had the patients remained in the acute care hospital for an additional 1 or 2 days and been sent directly home). These results emphasize the importance of monitoring the effects of cost containment and other systematic efforts to change patient care at the local level.

Physicians' changing attitudes toward guidelines

The objective of the study was to measure the change in physicians' attitudes toward preventive care guidelines over a 2-year period. The study was conducted at a Southern California managed care medical group that was experiencing intense price competition. We analyzed individualized survey responses of 62 HMO primary care physicians over the study period. We found that physicians increasingly believed that clinical guidelines were being used for cost containment (first survey 71% vs second survey 92%, p < .005) and less for quality improvement (first survey 85% vs second survey 67%, p < .008) over time. These findings may create a barrier to physicians' adoption of practice guidelines.

Role of transabdominal pelvic ultrasound and computed tomography in the detection of bladder involvement in advanced cancer of the cervix

The imaging data of 125 advanced cancer cervix patients attending the Institute Rotary Cancer Hospital between June 1992 and June 1994 was reviewed. The aim of the study was to assess the role of transabdominal pelvic ultrasound (TAPUS) and computed tomography (CT) in the detection of bladder involvement. TAPUS was performed in 65 patients (group I) and CT in 60 patients (group II). With respect to clinical stage, both groups were comparable. Cystoscopy was performed in all patients and the findings were taken as the gold standard for comparison of imaging data. The sensitivity, specificity and accuracy of TAPUS were 65, 94 and 75%, respectively, while those for CT were 80, 92 and 85%, respectively. Results of the present study reveal that the accuracy of TAPUS is comparable to the accuracy of other imaging modalities in the detection of bladder involvement in cervical cancer and that it should be used more frequently in developing countries that deal with a large number of cervical cancer patients in view of its easy availability, low cost and absence of exposure to radiation.

Tropical pulmonary eosinophilia: a comparative evaluation of plain chest radiography and computed tomography

Plain chest radiography and computed tomography (CT) of the chest were performed on 10 patients with tropical pulmonary eosinophilia (TPE). Chest radiographs revealed bilateral diffuse lesions in the lungs of all the patients with relative sparing of lower lobes in one patient. However, computed tomography revealed bilateral diffuse lung lesions in all of the patients with relative sparing of lower lobes in three patients. In seven (70%) of the 10 patients, CT provided additional information. Computed tomography was found to be superior for the detection of reticulonodular pattern, bronchiectasis, air trapping, calcification and mediastinal adenopathy. No correlation was found between pulmonary function and gas exchange data using CT densities. There was also no correlation between the absolute eosinophil count (AEC) and the radiological severity of lesions. In six patients, high-resolution CT (HRCT) was performed in addition to conventional CT (CCT), and nodularity of lesions was better appreciated in these patients. It is concluded from this study that CT is superior to plain radiography for the evaluation of patients with TPE. However, more work needs to be done to substantiate the results of the present study.

Correlation of computed tomography with second-look laparotomy in ovarian carcinoma

BACKGROUND

Cancer of the ovary is the second commonest gynaecological malignancy after cancer of the cervix. Surgery followed by cisplatin-based chemotherapy is the standard treatment approach. In patients with persistent disease, second-look laparotomy offers an opportunity to debulk the tumour. This is usually followed by an alternative method of chemotherapy. We compared the findings at surgery (second-look laparotomy) with the preoperative computed axial tomography scan assessments.

METHODS

Thirty-seven patients with epithelial ovarian carcinoma were assessed with computed axial tomography scans of the abdomen and pelvis prior to undergoing a second-look laparotomy.

RESULTS

Tumour was correctly identified on computed axial tomography scan in 11 patients who had macroscopic evidence of cancer at laparotomy. In 6 patients, both computed axial tomography scan and surgery showed no disease recurrence. In the remaining 20 patients, there was a mismatch between the computed axial tomography scan and the surgical findings. In 16 of the 20 (80%) patients, computed axial tomography scans were negative but tumour was present. When the tumour was less than 1.5 cm in diameter it was missed in 8, and when equal to or greater than 1.5 cm, it was missed in 5 patients. These small tumour deposits were located in the retroperitoneal area, under the dome of the diaphragm, omentum or peritoneum, liver surface, and in the pouch of Douglas. In one case each, infiltration of the urinary bladder, sigmoid colon and rectum was also not detected. In 4 patients, computed axial tomography scans showed tumour when none was present.

CONCLUSION

Computed axial tomography scan cannot detect small nodules often present in ovarian cancer, and thus even if a computed axial tomography scan is normal it should not exclude a second-look laparotomy.

Influence of vein valves in the development of arteriosclerosis in venoarterial grafts in the rabbit

Coronary saphenous vein grafts in human beings have a more limited long-term patency rate than internal thoracic artery grafts, primarily because of more rapid development of arteriosclerosis. The factors responsible for this increased susceptibility are not completely understood. To test the hypothesis that vein valves may influence this process, we studied 48 hypercholesterolemic rabbits with jugular vein grafts interposed into the carotid arterial circulation. In 24 animals (group A), the vein segments did not contain a vein valve. In the other 24 animals (group B), a vein valve was present. Both groups were further divided in four subgroups of six to be put to death at 2, 4, 6, and 8 weeks after the operation. All animals were fed a 2% cholesterol diet. At postmortem examination, alternate 2 mm sections were either stained with hematoxylin and eosin for histologic and morphometric studies or frozen in liquid nitrogen for immunohistochemistry and in situ hybridization studies. Proliferating cell nuclear antigen immunostaining was used to study cell proliferation. Wall thickness of vein grafts increased with time. During the first 2 weeks intimal and medial thickening was primarily due to an increase in numbers of cells. Between 2 and 6 weeks further intimal and medial thickening occurred, but without additional increase in cell numbers. After 6 weeks, foam cells and lipid deposits started to appear. By 8 weeks, changes identical to those seen in arteriosclerotic plaques in human beings were evident. These changes developed sooner and with more intensity in group B animals (p < 0.01 to 0.001), and they developed faster and with more severity in segments of vein located distal to the valve than in the segments located proximal to the valve (p < 0.001). This is the first controlled experiment demonstrating that the presence of valves in the vein segments is associated with augmented and accelerated intimal changes leading to vein atheromatosis.

Role of radiotherapy in cavernous hemangioma liver

OBJECTIVE

To study the effectiveness of local radiotherapy for controlling cavernous hemangioma of liver.

METHODS

This is a retrospective analysis of four diagnosed cases of cavernous hemangiomas of the liver treated with radiotherapy. Hepatic irradiation was given in a tumor dose of 30 Gy in 15 fractions over 3 weeks period.

RESULTS

Three of the four cases showed a complete clinical regression of the liver lesions over a period of 8-14 months, but in one case there was only 75% regression of the mass at 12 months of follow up.

CONCLUSIONS

Localized radiotherapy is effective in the treatment of giant cavernous hemangiomas of the liver and a tumor dose of 30 Gy is optimum with minimal morbidity.

Ultrasonography, computed tomography and percutaneous intervention in acute pancreatitis: a serial study

Fifty-seven patients (45 males, 12 females) with a clinical diagnosis of acute pancreatitis were serially evaluated by ultrasonography (US) and computed tomography (CT). Thirty patients had a single study, 18 had one follow-up study while 9 had two follow-up studies. The aetiology was gallstone disease in 26% of patients and a history of chronic alcohol abuse in only 16%. No cause could be identified in 47% of patients; 22% of US scans were unsatisfactory for the evaluation of pancreas whereas CT was uniformly satisfactory. Peripancreatic inflammation was detected in only 29% patients on US compared with 91% on CT. Pancreatic abscesses were detected in 8 patients on CT and gas was present in all of them. Fourteen patients underwent guided interventional procedures (US, 12; CT, 2). On follow up after 3 months, worsening of inflammation was detected in 11% patients on CT, which was not detected on US. It is concluded from this study that CT is far superior to US in the evaluation of acute pancreatitis, detection of peripancreatic inflammation and its extension into the retroperitoneal compartments and mesentery, and also for the evaluation of fluid collections, haemorrhage and abscesses. However, US provides easy guidance for percutaneous interventional procedures and can be used for follow-up scans.

Allergic bronchopulmonary aspergillosis: a comparative evaluation of computed tomography with plain chest radiography

Computed tomography (CT) was done in 15 consecutive patients with allergic bronchopulmonary aspergillosis (ABPA). When compared with chest X-ray, CT was found to be superior in the diagnosis of bronchiectasis in patients with ABPA. Of the 90 lobes studied, CT detected bronchiectasis in 57 lobes and plain chest X-ray in 44 lobes. In addition to central bronchiectasis, peripheral bronchiectasis was diagnosed with CT in 18 of the 57 lobes. Follow-up CT was done in two patients after treatment for detection of progression or regression of bronchiectatic lesions. One patient showed radiological as well as clinical improvement, while the other patient presented with a recurrence of symptoms 4 months after stopping treatment. Computed tomography showed radiological progression of bronchiectasis and the patient was successfully treated with corticosteroids (thus preventing further bronchial damage). It is concluded from this study that CT is superior to plain chest X-ray in the diagnosis of bronchiectasis in patients with ABPA. Being non-invasive, it is also helpful in monitoring the course of bronchiectasis in these patients.

The West Los Angeles Preterm Birth Prevention Project: II. Cost-effectiveness analysis of high-risk pregnancy interventions

OBJECTIVE

To examine the cost-effectiveness of the West Los Angeles Preterm Birth Prevention Project.

METHODS

Maternal and neonatal care data were collected on all preterm deliveries (150) and a random sample of term deliveries (140) from high-risk patients at both experimental and control clinic sites. Costs were determined for prenatal care, inpatient preterm labor, delivery and postpartum care, and newborn care. Cost calculations, weighted by the actual proportions of term and preterm births, were confirmed with square-root transformation and trimmed mean (2%) values.

RESULTS

When compared to control clinic high-risk patients, experimental clinic high-risk patients had an average cost savings of $2196 for newborn care (P = .02), resulting in a net savings of $1768 per high-risk mother-infant pair. Births before 32 weeks' gestation accounted for the greatest mean cost.

CONCLUSION

Programs of comprehensive prenatal care and patient education may be highly cost-effective for prevention of prematurity.

The West Los Angeles Preterm Birth Prevention Project. I. Program impact on high-risk women

OBJECTIVE

The primary objective of this prospective study was to test whether preterm birth prevention education plus increased clinic visits and selected prophylactic interventions reduce preterm birth.

STUDY DESIGN

Eight West Los Angeles prenatal county clinics, comparable with respect to selected demographics, were randomized to be either experimental or control clinics. High-risk patients in all clinics were identified with a risk scoring system derived from a similar population. High-risk patients (N = 1774) in experimental clinics were offered a program of education and more frequent visits and were randomized to receive various secondary intervention protocols in addition to the basic interventions of education and more frequent visits. Control clinic patients (N = 880) received standard county care.

RESULTS

Preterm birth rates were 19% lower among the experimental high-risk patients (7.4% vs 9.1%), and differences were significant (p < 0.05) when preterm risk was taken into account. There was no evidence to suggest that the secondary interventions provided added benefit over the primary intervention protocol of preterm birth prevention education and increased visits.

CONCLUSION

The 19% reduction in preterm birth rate observed in the experimental clinics suggest an overall program benefit from a protocol that offered education, more frequent visits, and greater attention given to patients while the selected interventions were applied.

Kinetic characteristics of soluble and brush border alkaline phosphatase and sucrase activities in developing rat intestine: effect of hormones

Suckling rat intestine contains 35 and 65% of the cytosolic and membrane-bound alkaline phosphatase (AP) activities. The corresponding values for sucrase were 20 and 80% respectively. The amount of the soluble enzymes was reduced to 7-11% in adult rat intestine. Administration of cortisone, thyroxine or insulin to suckling animals induced adult type distribution of the enzymes. There were apparent differences in kinetic characteristics of soluble and brush border enzymes, but the kinetic properties of the normally developed and hormone-induced AP and sucrase were essentially similar. This suggested identical nature of these enzymes under these conditions. A biphasic Arrhenius plot was obtained for AP in weaned and hormone injected pups with a break point around 18 degrees C, while the soluble enzyme yielded a monophasic curve (Ea = 8-11 kcal/mole). Arrhenius plot for sucrase was monophasic in the suckling, hormone-injected and adult rat intestine (Ea = 8.3-15.1 kcal/mole). Membrane-bound enzymes were generally labile, while soluble enzyme activities were stable to heat treatment (sucrase at 50 degrees C and AP at 60 degrees C) in various experimental groups.