A live-cell super-resolution technique demonstrated by imaging germinosomes in wild-type bacterial spores.

Time-lapse fluorescence imaging of live cells at super-resolution remains a challenge, especially when the photon budget is limited. Current super-resolution techniques require either the use of special exogenous probes, high illumination doses or multiple image acquisitions with post-processing or combinations of the aforementioned. Here, we describe a new approach by combining annular illumination with rescan confocal microscopy. This optics-only technique generates images in a single scan, thereby avoiding any potential risks of reconstruction related artifacts. The lateral resolution is comparable to that of linear structured illumination microscopy and the axial resolution is similar to that of a standard confocal microscope. As a case study, we present super-resolution time-lapse imaging of wild-type Bacillus subtilis spores, which contain low numbers of germination receptor proteins in a focus (a germinosome) surrounded by an autofluorescent coat layer. Here, we give the first evidence for the existence of germinosomes in wild-type spores, show their spatio-temporal dynamics upon germinant addition and visualize spores coming to life.

Improving outpatient diabetes management through a collaboration of six competing, capitated Medicare managed care plans.

This report addresses diabetes care in the managed care setting and improvement in care brought about by collaboration between 6 Medicare managed care plans (MCPs) and a Peer Review Organization (PRO). The objective was to improve the quality of care of outpatient diabetes patients provided by primary care physicians through the mutual collaboration of 6 Medicare managed care plans and a Medicare Peer Review Organization. The design involved pre-post intervention trial based on 2 random samples, a baseline sample drawn in 1995 and a remeasurement sample drawn in 1996. Medical records of patients in both samples were reviewed by the PRO to determine provision of 14 quality indicator services over a 1-year period. The setting was 6 Arizona Medicare managed care plans comprising approximately 40% of the Arizona Medicare population. Two random samples were drawn from type 2 diabetes patients continuously enrolled in the same managed care plan for at least 1 year. The intervention was comparative feedback of baseline data by the PRO, enabling each plan to compare itself to any other plan on any or all indicators. Each plan developed and implemented its own intervention in response to the 1995 baseline results. The main outcome measures were mean HbA1c, the proportion of HbA1c values below 8%, and positive change in provision of 14 quality indicator services. At postintervention remeasurement, mean HbA1c values fell from 8.9 +/- 2.2 to 7.9% +/- 2.1, and the proportion of patients with HbA1c values below 8.0% rose from 40% to 61.6%. The proportion of the 14 indicator services provided to patients rose from 35% to 55%. The mean number of physician office visits fell 13% and the number of services provided per visit doubled. We conclude that improving the process of care improves glycemic control. Better outpatient diabetes management in competing, capitated managed care plans is an attainable goal when mediated through a neutral third party such as a PRO.

Outpatient management of diabetes mellitus in five Arizona Medicare managed care plans.

We report findings on the outpatient management of diabetes mellitus in Medicare beneficiaries enrolled in five Arizona Medicare-managed care plans. These findings are the baseline of an ongoing collaboration between the Health Services Advisory Group, Inc., Arizona's Peer Review Organization (PRO), and the five plans whose object is improved care of diabetes patients. The purpose of the study was to determine congruity between quality indicators identified by the five plans and the care actually received by diabetes patients enrolled in the five plans. The five plans agreed on a common set of quality indicators, including 10 services and 10 measures of patient status. Each plan has identified its diabetic population, 75 of whom are randomly selected each quarter by the PRO for chart review and inclusion in the study. The findings in this report cover two quarters of data. Data from chart review were examined to determine the extent to which actual practice reflected the indicators. The mean patient age was 71.8, and for most patients onset occurred between 55 and 69 years of age. About 25% had a positive family history, and we estimate the annual incidence of diabetes in this population to be about 1.1%. Mean hemoglobin A1c (HbA1c) was 8.9 +/- 2.1%; 46% were hypertensive; 42% continued to smoke cigarettes; 36% had retinopathy; 20% had proteinuria; and only 22% were on some kind of exercise program. Thirty-two percent were hospitalized during the 1-year baseline period, and the average number of outpatient visits per patient was 11.1 +/- 7.4. When care provided to diabetes patients enrolled in the plans was compared with the 10 quality standards identified by the plans themselves, only two of these standards was attained in more than 60% of patients: blood pressure, 98.7%; and foot examination, 62.7%. Two standards were achieved less than one-third of the time: urine dipstick, 10.4%, and appropriate use of angiotensin-converting enzyme (ACE) inhibitors, 31.25%. The others were all between 40 and 55%. Of the 10 service standards, about one-third received 1-4, one-third received 5-6, and one-third received 7-10. Only 5% of patients received 9 or 10 services. Outpatient management of diabetes patients in managed-care plans is similar to that in fee-for-service. When compared with fee-for-service or another HMO, a higher proportion of Arizona-managed care patients had HbA1c, and a much lower proportion had a dipstick test for urine protein. Values for other variables were usually within 10 percentage points of each other. Regardless of payment scheme, diabetes care is characterized by inconsistencies, omissions, and a lower than desirable level of services. Although few patients received most of the indicator services, diabetes patients are nevertheless high utilizers of medical care, both in and out of the hospital. The hospitalization rate is twice that of Arizona Medicare beneficiaries as a whole, and the number of office visits is three or four times that reported in other studies. Further, it seems that many visits are required to achieve even these modest service levels. Had the average number of visits been six or less, HbA1c rates, for example, would have fallen to less than one-third in three of the five plans. We believe that these data are conservative because it is likely that some and perhaps most of these indicators are underreported. It should be emphasized that these are baseline data whose purpose is to provide a basis against which subsequent improvements many be measured.

Effect of heart rate alterations produced by atrial pacing on the pattern of diastolic filling in normal subjects.

To determine the effect of heart rate alterations on diastolic timing intervals and filling parameters, 10 normal patients were paced from the right atrium at 30 and 50 beats/min above their baseline rates. M-mode echocardiograms of the aortic valve, mitral valve and left ventricle were obtained and digitized at baseline and with each pacing rate. With increased atrial pacing, left ventricular systolic time became an increasingly greater proportion of cycle length while the diastolic filling period occupied a lesser proportion of the cycle length. The time to peak filling rate and the rapid filling period occupied a greater proportion of the diastolic filling period. The peak filling rate increased progressively with increased atrial pacing (baseline 128 +/- 19 mm/s, first paced rate 146 +/- 27 mm/s, p less than 0.05 vs baseline; second paced rate 167 +/- 23 mm/s, p less than 0.01 vs baseline and first paced rate). The early diastolic filling fraction and rapid filling fraction also increased with pacing. Increasing the heart rate resulted in an alteration of the time course of diastolic filling and extent of diastolic filling during the rapid filling period. Interventions that improve diastolic filling and increase heart rate may in part be due to heart rate changes.

Simplified count-based estimates of left ventricular volume.

Accurate count-based radionuclide estimates of left ventricular volume without the use of a blood sample have not been well described. Resting gated blood pool scans were obtained within 24 hours of catheterization in 31 patients (group 1), and simultaneously with thermodilution cardiac outputs in 29 other patients (group 2) at rest and during an induced-volume change (intervention). End-diastolic and end-systolic volumes were calculated from the single-plane angiogram in Group 1 and from the combination of thermodilution stroke volume and radionuclide ejection fraction in group 2. Excellent correlations were noted between scintigraphic counts and angiographic volumes (r = 0.964), between scintigraphic counts and thermodilution-derived volumes (r = 0.979), and between interventional scintigraphic counts and interventional thermodilution-derived volumes (r = 0.941). Thermodilution and scintigraphic volume changes during the intervention were well correlated (r = 0.85). Accurate count based estimates of left ventricular volume without a blood sample are feasible at rest and during an intervention.

Left ventricular diastolic filling in patients with left ventricular dysfunction.

The pattern of abnormal left ventricular diastolic filling and its specificity in coronary disease patients with severe left ventricular dysfunction has received little attention. We evaluated the left ventricular diastolic filling curve derived from gated blood pool scans in 21 normals, 61 coronary disease patients with ejection fractions less than or equal to 30%, and 51 congestive cardiomyopathy patients with ejection fraction less than or equal to 30%. The peak filling rate (PFR), peak ejection rate (PER), PFR/PER and the % stroke volume filled at 1/3 of diastole (%SV-1/3 DT) and at the end of the rapid filling period (%SV-RFP) were determined for each group. The PFR and PER were reduced in both coronary disease and congestive cardiomyopathy groups. The PFR/PER was increased in the coronary disease group (1.19 +/- 0.28) and congestive cardiomyopathy group (1.21 +/- 0.32) as compared to normals (0.93 +/- 0.20, P less than 0.001). A greater %SV-1/3 DT and %SV-RFP were noted in both coronary disease and congestive cardiomyopathy groups. Coronary disease and congestive cardiomyopathy patients with a mean pulmonary capillary pressure (PCP) greater than or equal to 18 mm Hg had a greater PFR/PER, %SV-1/3 DT, and %SV-RFP than patients with a PCP less than 18 mm Hg. An abnormal and nonspecific pattern of left ventricular diastolic filling is present in both coronary disease and congestive cardiomyopathy patients and is characterized by an increased PFR/PER, a greater %SV-1/3 DT, and a greater %SV-RFP. This pattern may be related to elevated PCPs.

Left ventricular diastolic filling in patients with coronary artery disease and normal left ventricular function.

Abnormal left ventricular diastolic filling (DF) has been noted in coronary disease (CD) patients with normal left ventricular function (NLVF). Inclusion of patients with regional wall disease, hypertension, and left ventricular hypertrophy may be responsible for abnormal DF. We evaluated left ventricular DF curves derived from gated blood pool scans in 21 normals (group 1), in 38 CD patients with NLVF specifically defined (group 2), and in 28 CD patients with ejection fractions greater than 50% and regional disease (group 3). The peak filling rate (PFR), mean filling rate (MFR), the percentage of stroke volume filled at one third of diastole (%SV-1/3 DT) and at the end of the rapid filling period (%SV-RFP) were determined. Groups 1 and 2 had similar DF parameters. Group 2 patients with 75% obstructive left anterior descending disease (LAD) had a reduced %SV-RFP and PFR (2.56 +/- 0.56 end-diastolic volumes/sec [EDV/S]) as compared to normals (3.11 +/- 0.65 EDV/S, p less than 0.01). Group 3 patients had a reduced PFR (2.14 +/- 0.53 EDV/S, p less than 0.001), MFR, %SV-1/3 DT, and %SV-RFP. DF in CD patients with NLVF was similar to normals in a select group of patients but was abnormal in patients with regional disease and greater than 75% LAD disease with NLVF.

Pattern of left ventricular diastolic filling in chronic aortic regurgitation: a gated blood pool assessment.

Limited information exists regarding the pattern of left ventricular diastolic filling in moderate to severe chronic aortic regurgitation (AR). The left ventricular diastolic filling curve derived from gated blood pool scans was evaluated in 24 normal subjects and 29 patients with AR. The peak filling rate (PFR), mean filling rate (MFR), peak ejection rate (PER), PFR/MFR, PFR/PER, and the time of the rapid filling period divided by the diastolic time were determined. PFR, MFR and PER were calculated as end-diastolic volumes per second (EDV/s). PFR was lower in the AR group than in the normal subjects (2.24 +/- 0.70 vs 3.09 +/- 0.71 EDV/s, p less than 0.001). Similarly, MFR was lower in the AR group (1.31 +/- 0.40 vs 1.63 +/- 0.29 EDV/s, p less than 0.01). PER was also reduced in the AR group. Both PFR/MFR and PFR/PER were reduced, while the ratio of rapid filling period to diastolic time was longer in the AR group than in normal subjects. Clinical evidence of congestive heart failure occurred in 8 patients in the AR group. Diastolic filling variables were not significantly different from the asymptomatic subgroup of patients with AR, but were abnormal when compared with those of normal subjects. In patients with AR, an abnormal pattern of diastolic filling was noted, consisting of a reduced PFR, MFR and PFR/ with a more linear pattern of filling (reduced PFR/MFR) during a longer rapid filling period.

Evaluation of habitual excessive alcohol consumption on myocardial infarction risk in coronary disease patients.

Overt coronary heart disease does occur at times in a setting of alcoholism. In an attempt to test the hypothesis that habitual excessive drinking may have an aggravating effect upon coexisting ischemic heart disease and may help precipitate new coronary events, we compared myocardial infarct prevalence among heavy drinkers and non-heavy drinkers with angiographically documented coronary artery disease. Infarct prevalence was found to be higher for heavy drinkers than for non-heavy drinkers under age 60 years, after controlling for differences in smoking habits and underlying atherosclerosis severity. A reversal in trend which may be due to the operation of selective factors causing premature coronary death among alcoholics was observed for individuals above age 60 years. These results, although open to differing interpretations, are consistent with the notion that heavy drinking has a destabilizing effect upon preexisting ischemic heart disease and may increase acute coronary event risk.

Diabetes and hypercholesterolemia among patients with calcific aortic stenosis.

To help clarify the etiology and pathogenesis of calcific aortic stenosis, we studied retrospectively the relationship existing between that condition and two presumptive risk factors: diabetes and hypercholesterolemia. Fifty-four patients with isolated aortic stenosis, undergoing cardiac catheterization, were compared to patients without aortic stenosis who underwent angiography for unrelated reasons. The effect of diabetes and hypercholesterolemia, singly and in combination, upon the prevalence of aortic stenosis, was tested by various methods, including mathematical model fitting: Both study factors were found to be associated with aortic stenosis; their combined effect upon the prevalence of that disease appeared to be multiplicative. These findings suggest that diabetes and hypercholesterolemia may play a role in the causation of aortic stenosis. Further studies among unselected populations are needed to confirm the existence of the associations uncovered.

Unsuspected purulent pericarditis detected by gallium-67 scanning: a case report.

A Ga-67 scan performed because of a suspected intraabdominal infection demonstrated marked pericardial uptake of the isotope instead, and thus provided the first clue to the diagnosis of purulent pericarditis. Subsequent studies and surgery revealed an esophagopericardial fistula, gas in the pericardial sac, and purulent pericarditis caused by multiple bacteria. This report presents an unusual cause of pericardial uptake of Ga-67. The use of Ga-67 scanning of diagnose purulent pericarditis in the absence of typical clinical findings is illustrated.

Surgical treatment of acute aortic regurgitation in infective endocarditis.

During a six-year period 15 consecutive patients with isolated aortic regurgitation due to infective endocarditis were encountered. None had prior significant aortic valve disease. Elective valve replacement was performed in 13 patients; emergency operation was needed in only 1 patient because of intractable pulmonary edema. One patient died suddenly from acute heart block while undergoing medical treatment. Preoperative cardiac catheterization studies in 10 of the 14 patients revealed gross elevations of left ventricular end-diastolic pressure, pulmonary hypertension, depressed cardiac output, and 3 to 4+ aortic regurgitation. There was 1 early and 1 late postoperative death, both due to systemic embolism, yielding an overall surgical mortality of 14%. After a mean follow-up of 18 months, 10 of the 11 patients are in New York Heart Association Functional Class I. Most patients with acute aortic regurgitation secondary to infective endocarditis have clinically observable congestive heart failure and will eventually require valve replacement. If congestive heart failure can be stabilized by a medical regimen, a course of antibiotic therapy can be administered and elective valve replacement can be performed. The time taken for preoperative antibiotic treatment is not associated with irreversible myocardial damage sufficient to influence the results of operation.

Permanent pacing in disorders of sinus node function.

Thirty-three patients with disorders of sinus node function treated with permanent endocardial pacemakers were evaluated. Study of the underlying heart rate and rhythm was accomplished by external inhibition of pacemakers. The development of stable atrial fibrillation was documented in 7 out of 29 patients studied and effectively terminated the syndrome of sinus node dysfunction. Embolic complications appeared to be an important factor in the morbidity and mortality in patients with changing supraventricular rhythms. Pacemaker therapy effectively controlled syncopal episodes due to bradycardia, but recurrent episodes of tachycardia and problems associated with this remained unaffected.