P4353Global longitudinal strain is a measure of subclinical left ventricular dysfunction in chronic inflammatory autoimmune conditions

Background

Myocardial deformation indices are proposed to be a more sensitive marker of subclinical dysfunction compared to standard measures of left ventricular (LV) systolic function. We hypothesize that subclinical myocardial dysfunction is present in chronic inflammatory autoimmune diseases such as Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA), despite both conditions being mediated by different pro-inflammatory modulators.

Purpose

Identify subclinical myocardial dysfunction through assessment of global longitudinal strain in two different chronic autoimmune conditions, SLE and RA.

Methods

Consecutive patients admitted to our institution with known history of SLE or RA (>1 year disease activity) were examined. Patients with preexisting cardiac disease, LVEF <50% and those without comprehensive transthoracic echocardiograms (TTE) were excluded. Mean longitudinal LV strain was performed offline using vendor-independent software (TomTec v4.6) and compared to age- and gender-matched controls with normal LV function and no history of cardiac disease.

Results

Of the 86 patients examined (mean age 53.01±21.74, 85.4% female), 51 (59.3%) had SLE and 35 (40.7%) had RA. No significant difference in BMI, hypertension, hypercholesterolemia, diabetes, obesity, obstructive sleep apnea and stroke was observed between controls and patients with SLE or RA. While there was no significant difference in LVEF between RA patients and matched controls, there was a significantly lower GLS in the RA cohort. Conversely, patients with SLE had significantly lower LVEF and GLS when compared to matched controls, despite LVEF being in the normal range. See Table 1. Receiver operator curve analysis revealed that mean GLS is a better discriminator for autoimmune disease with an area under the curve of 0.829 (95% CI, 0.77 to 0.89; p<0.01) compared to LVEF with an area under the curve of 0.632 (95% CI, 0.55 to 0.72; p<0.01).

Echocardiographic Parameters SLE (n=51) Controls (n=51) Sig (p value) RA (n=35) Controls (n=35) Sig (p value) LVEDV (mls) 102±30 85±20 <0.01 84±28 89±30 0.43 LVESV (mls) 36±17 29±9 0.02 26±14 30±12 0.24 Biplane LVEF % 59±6 63±4 <0.01 62±6 62±5 0.81 LV Mass (grams/m2) 96±34 72±20 <0.01 79±26 82±23 0.67 LV Mean GLS % 16.7±2.8 21.3±2 <0.01 17.8±1.7 19.1±2.5 0.02

Conclusions

Our results suggest that chronic inflammatory conditions (SLE and RA) are associated with subclinical cardiac dysfunction. Impaired GLS may reflect early myocardial damage and be used as a tool for screening of patients with inflammatory conditions.

Acknowledgement/Funding

None

Are adverse outcome rates higher in multiple sclerosis patients after total hip arthroplasty?

Aims

This study compared multiple sclerosis (MS) patients who underwent primary total hip arthroplasty (THA) with a matched cohort. Specifically, we evaluated: 1) implant survivorship; 2) functional outcomes (modified Harris Hip Scores (mHHS), Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS JR), and modified Multiple Sclerosis Impact Scale (mMSIS) scores (with the MS cohort also evaluated based on the disease phenotype)); 3) physical therapy duration and return to function; 4) radiographic outcomes; and 5) complications.

Patients and Methods

We reviewed our institution's database to identify MS patients who underwent THA between January 2008 and June 2016. A total of 34 MS patients (41 hips) were matched in a 1:2 ratio to a cohort of THA patients who did not have MS, based on age, body mass index (BMI), and Charlson/Deyo score. Patient records were reviewed for complications, and their functional outcomes and radiographs were reviewed at their most recent follow-up.

Results

Compared with the matched cohort, MS patients had lower all-cause implant survivorship at eight years (91.5% (95% confidence interval (CI) 82.7 to 100) vs 98.7% (95% CI 96.2 to 100)) (p = 0.033), lower mHHS scores (66 vs 80, p < 0.001), and HOOS JR scores (79 vs 88, p = 0.009). Multiple sclerosis patients also required more physiotherapy (five weeks vs three weeks, p = 0.002) and took longer to return to baseline (seven weeks vs five weeks, p = 0.010) than the matched cohort. Furthermore, MS patients had more complications than the non-MS patients (six vs zero, p < 0.001). The worse outcomes of the MS group can potentially be explained by predisposition of these patients to mechanical complications and progression of their disease during the period of this study, as demonstrated by worsening of the mMSIS scores (2.9 vs 3.4; p = 0.008).

Conclusion

MS patients had lower implant survivorship, lower functional outcome scores, and increased complication rates; in addition, MS patients took longer to return to their baseline functional level after THA. Cite this article: Bone Joint J 2018;100-B:875-81.

Structural analysis of a set of proteins resulting from a bacterial genomics project

The targets of the Structural GenomiX (SGX) bacterial genomics project were proteins conserved in multiple prokaryotic organisms with no obvious sequence homolog in the Protein Data Bank of known structures. The outcome of this work was 80 structures, covering 60 unique sequences and 49 different genes. Experimental phase determination from proteins incorporating Se-Met was carried out for 45 structures with most of the remainder solved by molecular replacement using members of the experimentally phased set as search models. An automated tool was developed to deposit these structures in the Protein Data Bank, along with the associated X-ray diffraction data (including refined experimental phases) and experimentally confirmed sequences. BLAST comparisons of the SGX structures with structures that had appeared in the Protein Data Bank over the intervening 3.5 years since the SGX target list had been compiled identified homologs for 49 of the 60 unique sequences represented by the SGX structures. This result indicates that, for bacterial structures that are relatively easy to express, purify, and crystallize, the structural coverage of gene space is proceeding rapidly. More distant sequence-structure relationships between the SGX and PDB structures were investigated using PDB-BLAST and Combinatorial Extension (CE). Only one structure, SufD, has a truly unique topology compared to all folds in the PDB.

Nutritive blood flow affects microdialysis O/I ratio for [(14)C]ethanol and (3)H(2)O in perfused rat hindlimb

Changes in the microdialysis outflow-to-inflow (O/I) ratio for [(14)C]ethanol and (3)H(2)O were determined in the perfused rat hindlimb after increases and decreases in nutritive flow mediated by the vasoconstrictors norepinephrine (NE) and serotonin (5-HT), respectively. Microdialysis probes (containing 10 mM [(14)C]ethanol and (3)H(2)O pumped at 1 or 2 microl/min) were inserted through the calf of the rat. Hindlimb perfusion flow rate was varied from 6 to 56 ml x min(-1) x 100 g(-1) in the presence of NE, 5-HT, or saline vehicle. The O/I ratios for both tracers were determined at each perfusion flow rate, as was perfusion pressure, oxygen uptake (a surrogate indicator of nutritive flow), and lactate release. Both tracers showed a decreased O/I ratio as hindlimb perfusion flow was increased, with [(14)C]ethanol being higher than (3)H(2)O. NE decreased the O/I ratio compared with vehicle, and 5-HT increased it for both tracers and both microdialysis flow rates. We conclude that the microdialysis O/I ratio, while able to detect changes in total flow, is also sensitive to changes in nutritive and nonnutritive flow, where the latter still extracts tracer, but less than the former.

The Everglades Nutrient Removal Project test cells: STA optimization--status of the research at the north site

The Everglades is an oligotrophic ecosystem that is being adversely impacted by hydrologic changes and nutrient-rich runoff generated from urban and agricultural sources. The Stormwater Treatment Area (STA) Optimization Research and Monitoring program is mandated by the 1994 Everglades Forever Act and will assist the South Florida Water Management District in developing operational strategies that maximize performance of emergent macrophyte STAs. The primary objective of this research is to examine how hydrologic conditions may influence STA performance. The study was conducted in 0.2 ha, shallow, fully lined test cells located within the perimeter of the Everglades Nutrient Removal Project. Experiments were designed to examine the effect of increased and decreased hydraulic loading rate (HLR) on wetland performance and to determine, if possible, the HLR at which STA treatment fails to reduce outflow total phosphorus concentration to the interim target of 50 microg-P/L. To date, two HLR experiments have been completed at the north site. Preliminary data indicated at all HLRs tested that particulate phosphorus and dissolved organic phosphorus ratios remained virtually unchanged from inflow to outflow. The dissolved organic and particulate compounds within these test cells are extremely recalcitrant, and are not easily assimilated within the system. High HLRs may not result in detention times long enough to mineralize these forms into easily assimilated inorganic compounds, resulting in mean TP concentrations greater than 50 microg-P/L.

Predictors of rehospitalization for symptomatic venous thromboembolism after total hip arthroplasty

BACKGROUND

Recent studies have shown that symptomatic venous thromboembolism after total hip arthroplasty most commonly develops after the patient is discharged from the hospital. Risk factors associated with these symptomatic thromboembolic events are not well defined.

METHODS

Using administrative data from the California Medicare records for 1993 through 1996, we identified 297 patients 65 years of age or older who were rehospitalized for thromboembolism within three months after total hip arthroplasty. We compared demographic, surgical, and medical variables potentially associated with the development of thromboembolism in these patients and 592 unmatched controls.

RESULTS

A total of 89.6 percent of patients with thromboembolism and 93.8 percent of control patients were treated with pneumatic compression, warfarin, enoxaparin, or unfractionated heparin, alone or in combination. In addition, 22.2 percent and 29.7 percent, respectively, received warfarin after discharge. A body-mass index (the weight in kilograms divided by the square of the height in meters) of 25 or greater was associated with rehospitalization for thromboembolism, with an odds ratio of 2.5 (95 percent confidence interval, 1.8 to 3.4). In a multivariate model, the only prophylactic regimens associated with a reduced risk of thromboembolism were pneumatic compression in patients with body-mass indexes of less than 25 (odds ratio, 0.3; 95 percent confidence interval, 0.2 to 0.6) and warfarin treatment after discharge (odds ratio, 0.6; 95 percent confidence interval, 0.4 to 1.0).

CONCLUSIONS

In patients who underwent total hip arthroplasty, a body-mass index of 25 or greater was associated with subsequent hospitalization for thromboembolism. Pneumatic compression in patients with a body-mass index of less than 25 and prophylaxis with warfarin after discharge were independently protective against thromboembolism.

Interaction between metabolism and flow in tendon and muscle

Blood vessels supplying the musculotendinous region of tendons, including interfibrillar connective tissue, represent a parallel vascular network to that supplying muscle fibers. Reciprocal control by vasomodulators and neural input determines relative flow in each network, and therefore relative supply of nutrients and hormones. Vessels supplying the tendon support fat cells and may function as a non-nutritive network within muscle groups to regulate resting muscle energy metabolism and to act as a flow reservoir for nutrient delivery in exercise.

Relationship of MTT reduction to stimulants of muscle metabolism

MTT, a positively charged tetrazolium salt, is widely used as an indicator of cell viability and metabolism and has potential for histochemical identification of tissue regions of hypermetabolism. In the present study, MTT was infused in the constant-flow perfused rat hindlimb to assess the effect of various agents and particularly vasoconstrictors that increase muscle metabolism. Reduction of MTT to the insoluble formazan in muscles assessed at the end of experiments was linear over a 30 min period and production rates were greater in red fibre types than white fibre types. The vasoconstrictors, norepinephrine (100 nM) and angiotensin (10 nM) decreased MTT formazan production in all muscles but increased hindlimb oxygen uptake and lactate efflux. Veratridine, a Na(+) channel opener that increases hindlimb oxygen uptake and lactate efflux without increases in perfusion pressure, also decreased MTT formazan production. Membrane stabilizing doses (100 microM) of (+/-)-propranolol reversed the inhibitory effects of angiotensin and veratridine on MTT formazan production. Muscle contractions elicited by stimulation of the sciatic nerve, reversed the norepinephrine-mediated inhibitory effects on MTT formazan production, even though oxygen consumption and lactate efflux were further stimulated. Stimulation of hindlimb muscle oxygen uptake by pentachlorophenol, a mitochondrial uncoupler, was not associated with alterations in MTT formazan production. It is concluded that apart from muscle contractions MTT formazan production does not increase with increased muscle metabolism. Since the vasoconstrictors angiotensin and norepinephrine as well as veratridine activate Na(+) channels and the Na(+)/K(+) pump, energy required for Na(+) pumping may be required for MTT reduction. It is unlikely that vasoconstrictors that stimulate oxygen uptake do so by uncoupling respiration.

Structural genomics in the post-genomics era - the shapes of things to come

The overwhelming success of the current genomic sequencing efforts has spawned analogous efforts in the structural biology community. These new research efforts, termed 'structural genomics', seek to create and execute high-throughput structure determination that would allow scientists to obtain hundreds to thousands of relevant macromolecular structures in a fraction of the time required today. Groups in academia, national laboratories and industry are launching such efforts, each examining a different set of model organisms and each with a different research model. This review will present the current structural genomics efforts and the data that have been derived from these efforts to date. The utility of these projects to pharmaceutical drug discovery efforts will also be presented.

Nutritive and non-nutritive blood flow: rest and exercise

There is growing evidence to support the notion of two vascular routes within, or closely associated with skeletal muscle. One route is in intimate contact with muscle cells (hence is known as 'nutritive') and the other functions as a vascular shunt (and has had the interesting misnomer of 'non-nutritive'). Recent findings suggest that the 'non-nutritive' route may, in part, be those vessels in closely associated (interlacing?) connective tissue that nourishes attached fat cells, and may form the basis of 'marbling' of muscle in obesity. In addition, embolism studies using various size microspheres indicate that the 'non-nutritive' vessels are likely to be capillaries fed by terminal arterioles that branch from the same transverse arterioles as those supplying terminal arterioles of the muscle capillaries (i.e. two vascular systems operating in parallel). The proportion of flow distributed between the two routes is tightly regulated and controls muscle metabolism and contraction by regulating hormone and substrate delivery as well as product removal. Because a high proportion of nutritive flow may elevate the set point for basal metabolism, a low proportion of nutritive flow in muscle at rest confers an evolutionary advantage, particularly when food is scarce. In addition, the proportion of flow that is carried by the non-nutritive routes at rest affords a flow reserve that can be switched to the nutritive route to amplify nutrient supply during exercise. Alternatively the non-nutritive route may allow flow to escape when active muscle contraction compresses its nutritive capillaries. Thus rhythmic oscillation of blood flow between the non-nutritive and nutritive networks may aid the muscle pump.

Increased metabolism of infused 1-methylxanthine by working muscle

Exogenous substrates for capillary endothelial enzymes have potential as markers for changes in capillary recruitment (albeit nutritive flow). The metabolism of infused 1-methylxanthine (1-MX) to 1-methylurate (1-MU) by capillary endothelial xanthine oxidase of the constant-flow perfused rat hindlimb was shown previously to decrease with oxygen uptake (VO2) when nutritive flow was decreased. In the present study, the metabolism of 1-MX was investigated under conditions when VO2 and nutritive flow are known to increase during muscle contraction. The constant-flow red blood cell-perfused rat hindlimb at 37 degrees C was used with sciatic nerve stimulation, and perfusate samples from whole hindlimb and working muscles taken for analysis of oxygen, lactate, 1-MX and 1-MU. Flow to muscle was assessed separately using fluorescent microspheres and was found to increase 2.3-fold to the working muscles while flow to the non-working leg muscles decreased to compensate. The activity of xanthine oxidase of whole muscle extracts was not altered by contraction. Samples from the vein draining the working muscles, and microsphere measurements of flow, indicated increased VO2 (5.5-fold to 249.2 +/- 43.1 micromol h-1 g-1, P < 0.001), and 1-MX conversion (2.5-fold to 1.87 +/- 0.25 micromol h-1 g-1, P < 0.01) (SEM are shown). It is concluded that as 1-MX metabolism parallels VO2, this substrate may be a useful indicator of changes in capillary (nutritive) surface area in muscle.

Outcome following acute myocardial infarction: are differences among physician specialties the result of quality of care or case mix?

BACKGROUND

Studies to determine whether care by cardiologists improves the survival of patients with acute myocardial infarction (MI) have produced conflicting results, and it is not known what accounts for differences in patient outcome by physician specialty.

OBJECTIVES

To evaluate whether cardiologists provide more recommended therapies to elderly patients with acute MI and, if so, to determine whether variations in processes of care account for differences in patient outcome.

DESIGN

Retrospective cohort study using medical chart data and administrative data files.

SETTING

All nonfederal acute care hospitals in California.

PATIENTS

A cohort of 7663 Medicare beneficiaries 65 years and older directly admitted to the hospital with a confirmed acute MI from April 1994 to July 1995 with complete data regarding potential contraindications to recommended therapies.

MAIN OUTCOME MEASURES

Percentage of "good" and "ideal" candidates for a given acute MI therapy who actually received that therapy, percentage who received exercise stress testing or coronary angiography, percentage who underwent revascularization, and 1-year mortality, stratified by specialty of the attending physician.

RESULTS

During hospitalization, good candidates for aspirin were more likely to receive aspirin if they were treated by cardiologists (87%) than by medical subspecialists (73%; P<.001), general internists (84%; P = .003), or family practitioners (81%; P<.001). Cardiologists were also more likely to treat good candidates with thrombolytic therapy (51%) than were medical subspecialists (29%; P<.001), general internists (40%; P<.001), or family practitioners (27%; P<.001). Patients of cardiologists were 2- to 4-fold more likely to undergo a revascularization procedure. Despite these differences in utilization, we found similar 30-day mortality rates across physician specialties. However, 1-year mortality rates were greater for patients treated by medical subspecialists (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.6-2.3), general internists (OR, 1.4; 95% CI, 1.3-1.6), and family practitioners (OR, 1.7; 95% CI, 1.4-1.9) than for those treated by cardiologists. Adjusting for differences in patient and hospital characteristics markedly reduced the ORs for those treated by medical subspecialists (OR, 1.2; 95% CI, 0.9-1.4), general internists (OR, 1.1; 95% CI, 1.0-1.3), and family practitioners (OR, 1.3; 95% CI, 1.1-1.6), whereas further adjustment for medication use and revascularization procedures had little effect.

CONCLUSIONS

Differences in the use of recommended therapies by physician specialty are generally small and do not explain differences in patient outcome. In comparison, differences among patients treated by physicians of various specialties (case mix) have a large impact on patient outcome and may account for the residual survival advantage of patients treated by cardiologists. With the exception of the in-hospital use of aspirin, recommended MI therapies are markedly underused, regardless of the specialty of the physician.

Contribution of mitochondrial proton leak to respiration rate in working skeletal muscle and liver and to SMR

Proton pumping across the mitochondrial inner membrane and proton leak back through the natural proton conductance pathway make up a futile cycle that dissipates redox energy. We measured respiration and average mitochondrial membrane potential in perfused rat hindquarter with maximal tetanic contraction of the left gastrocnemius-soleus-plantaris muscle group, and we estimate that the mitochondrial proton cycle accounted for 34% of the respiration rate of the preparation. Similar measurements in rat hepatocytes given substrates to cause a high rate of gluconeogenesis and ureagenesis showed that the proton cycle accounted for 22% of the respiration rate of these cells. Combining these in vitro values with literature values for the contribution of skeletal muscle and liver to standard metabolic rate (SMR), we calculate that the proton cycle in working muscle and liver may account for 15% of SMR in vivo. Although this value is less than the 20% of SMR we calculated previously using data from resting skeletal muscle and hepatocytes, it is still large, and we conclude that the futile proton cycle is a major contributor to SMR.

Class-directed structure determination: foundation for a protein structure initiative

The recent sequencing of many complete genomes, combined with the development of methods that allow rapid structure determination for many proteins, has changed the way in which protein structure determinations can be approached. One-by-one determinations of individual protein structures will soon be augmented by class-directed structure analyses in which a group of proteins is targeted and structures of representative members are determined and used to represent the entire group. Such a shift in approach would be the foundation for a broad protein structure initiative targeting classes of proteins important for biotechnology and for a fundamental understanding of protein function.

Stimulation and inhibition of resting muscle thermogenesis by vasoconstrictors in perfused rat hind limb

Angiotensin (AII) and serotonin (5-HT) are both vasoconstrictors of the constant-flow perfused rat hind limb that have opposite effects on thermogenesis, possibly the result of differing effects on vascular flow distribution between nutritive and non-nutritive pathways. In the present study interaction between the two opposing agents was examined with the expectation that the combined presence would show additive effects on pressure and mutually neutralizing effects on thermogenesis. Thus doses of AII and 5-HT that gave similar, but opposite, quantitative effects on thermogenesis were infused alone, in combination one after the other, or in combination with the order reversed, and the effects on perfusion pressure (PP) and thermogenesis (oxygen uptake, VO2) were compared. AII (3 nM) alone increased PP by 15+/-1 mmHg (1 mmHg = 133.3 Pa) and VO2 by 3.1-/+0.2 micromol.h(-1).g(-1), whereas 5-HT (1 microM) alone increased PP by 75+/-6 mmHg and inhibited VO2 by 3.9+/-0.2 micromol.h(-1).g(-1). When added in combination, the outcome depended on the order of addition. Following AII, infusion of 5-HT further increased PP by 160+/-11 mmHg and decreased VO2 by 6.3+/-0.2 micromol.h(-1)g(-1). Following 5-HT, infusion of AII further increased PP by 28+/-4 mmHg and increased VO2 by only 1.8+/-0.3 micromol.h(-1).g(-1). The prior presence of 5-HT (1 microM) shifted the AII dose-response curves for VO2 and pressure to the right and left, respectively. The prior infusion of AII increased the dose-dependent response to 5-HT in terms of both the inhibition of VO2 and the increase in PP. At low doses of 5-HT (10(-8)-10(-7) M), but not alpha-methyl serotonin (alphaMT), there was a marked vasodilatation-associated inhibition of AII-mediated increase in VO2. Overall the data show that the combined effect of AII and 5-HT differed from the simple addition of each separately. Since the order of addition appears to be critical in terms of thermogenic outcome, it is concluded that each vasoconstrictor exerts a specific hemodynamic action to affect access of the other to vascular receptor sites. These findings are consistent with the previously reported effects of these vasoconstrictors on substrate and insulin access to muscle of the perfused rat hind limb.

Vascular control of nutrient delivery by flow redistribution within muscle: implications for exercise and post-exercise muscle metabolism

There is evidence for non-nutritive flow routes within, or associated with, skeletal muscle. Large capillary-like structures are possible candidates. The proportion of flow distributed between nutritive and non-nutritive routes appears to be tightly regulated and can control muscle metabolism and contraction by regulating delivery and product removal. The portion of flow that is carried by the non-nutritive routes at rest affords a flow reserve for amplifying nutrient delivery as muscle begins to work and may determine post-exercise metabolism. Inappropriate signals, however, may diminish nutritive flow to the detriment of muscle performance and post-exercise recovery. New technologies should allow the identification of the non-nutritive routes.

Microvascular regulation of muscle metabolism

Nutrient and hormone delivery to skeletal muscle plays a major role in the regulation of metabolism of this tissue. Compromised perfusion, leading to the exclusion of single capillaries or groups of capillaries, can result from the inability of the cardiovascular system to maintain adequate total blood flow. Recent new data, however, indicate that nutrient delivery to skeletal muscle may not simply equate to total blood flow, but the partitioning between two circulatory systems, nutritive and non-nutritive, associated with each muscle. A number of hormones and neural mechanisms have now been identified that control the proportion of nutritive to non-nutritive flow. In addition, muscle metabolism and contractile performance have been shown to correlate with the extent of nutritive flow and inversely with non-nutritive flow, where the latter occurs in closely associated connective tissue. This review presents some of the evidence supporting the dual circulatory system model of muscle and the implications it may have in the management and treatment of patients subjected to shock, trauma, heart failure and long periods of immobilization.

Vessels supplying septa and tendons as functional shunts in perfused rat hindlimb

An assessment was made of the relationship between vasoconstrictor-mediated changes in metabolism and the apparent flow in putative nonnutritive vessels of muscle located on tendon. Surgically isolated rat hindlimbs were perfused at constant flow while monitoring perfusion pressure and venous pO2. In addition exposed tibial tendon vessels of the biceps femoris muscle of the perfused leg were positioned either under a surface fluorometer probe to monitor signal strength when pulses of fluorescein isothiocyanate dextran were infused or over the objective lens of an inverted microscope for photography when pulses of India ink were infused. Measurements were conducted under steady state with vehicle, norepinephrine, or serotonin infused. Norepinephrine increased perfusion pressure and oxygen uptake (VO2), but decreased fluorescence signal from the tendon vessels. Photomicroscopy confirmed that the vessels had generally decreased in diameter. Serotonin also increased perfusion pressure but decreased VO2 and increased fluorescence signal from the tendon vessels. Photomicroscopy confirmed that serotonin infusion had led to a marked increase in diameter of the vessels. It is concluded that a reciprocal relationship exists between resting muscle metabolism as controlled by vasoconstrictors and flow-through muscle tendon vessels.

Norepinephrine and serotonin vasoconstriction in rat hindlimb control different vascular flow routes

The vasoconstrictors, norepinephrine at low dose ( < or = 0.1 microM; LDNE) and serotonin (5-HT), produce opposing metabolic effects in the constant-flow perfused rat hindlimb characterized by increased and decreased oxygen uptake, respectively. In the present study, the effects of each vasoconstrictor are compared in the red blood cell-free buffer-perfused hindlimb on postequilibration endogenous red blood cell efflux, vascular entrapment of fluorescein-labeled dextran (Fx), and vascular corrosion casting by use of 30-micron spheres of methyl methacrylate (MM). A marked transient washout of red blood cells occurred immediately in association with vasoconstriction induced by LDNE that was not apparent when a similar extent of vasoconstriction was induced by 5-HT. Fx perfusions indicated that LDNE recruited a new vascular space that was reaccessed by a second exposure to the vasoconstrictor. 5-HT closed off a previously perfused vascular space that was reaccessed when the vasoconstrictor was removed. Corrosion casting of the arterial tree with MM showed no increase in cast weight, but more vessels filled because of LDNE. Higher doses of NE (2.5 microM) or 5-HT caused a marked decrease in cast weight with fewer vessels filled. The data suggest that LDNE and 5-HT, in association with vasoconstriction at different sites, control different capillary flow routes in the hindlimb that in turn may influence metabolism by increasing or decreasing nutrient access, respectively.

Angiotensin II: endothelium-derived nitric oxide interaction in conscious rats

In anesthetized rats, renal perfusion is largely regulated by a balance between the vasodilator influence of endothelium-derived nitric oxide (EDNO) and angiotensin II (AII)-mediated vasoconstriction. However, in conscious rats, which are characterized by lower PRA, the influence of AII is largely dissipated. To determine whether chronically increasing PRA enhances the interaction between AII and EDNO in regulating renal perfusion, radioactive microspheres were used to assess RBF in conscious sodium-depleted rats. PRA of control rats on a standard diet was 2.3 +/- 0.3 ng of AI/mL per hour compared with 16.8 +/- 1.5 ng of AI/mL per hour (P < 0.001) for rats on a sodium-restricted diet. In 12 rats on a standard diet, the inhibition of EDNO synthesis with L-Nw-nitroarginine methyl ester (L-NAME) increased blood pressure (BP) from 111 +/- 2 to 135 +/- 3 (P < 0.001) and decreased RBF by 47% (from 8.0 +/- 0.6 to 4.3 +/- 0.3 mL/min per gram kidney wt; P < 0.001). Renal vascular resistance (RVR) increased by 132% (from 14.9 +/- 1.2 to 34.7 +/- 3.3 resistance units (RU); P < 0.001). Pretreatment with Losartan, an AII receptor antagonist, did not modify the changes in BP, RBF, and RVR induced by L-NAME.(ABSTRACT TRUNCATED AT 250 WORDS)

Survey of physician practice behaviors related to diabetes mellitus in the U.S. Physician adherence to consensus recommendations

OBJECTIVE

To summarize the frequency of physician adherence to consensus recommendations for prevention of diabetic complications.

RESEARCH DESIGN AND METHODS

Survey data from a nationwide stratified probability sample of primary-care physicians were analyzed. Adherence to recommendations were reported by physician specialty, age-group, and type of diabetes treated.

RESULTS

Adherence was high for eye exams, blood pressure measurements, neurological and circulatory exams, and laboratory procedures using blood. Adherence was low for examination of the teeth and gums, examination of the feet, and laboratory procedures involving the collection of urine. Internists generally had the highest adherence rates and pediatricians the lowest. Reported adherence decreased with physician age. Adherence was higher for the management of individuals with IDDM than for those with NIDDM.

CONCLUSIONS

Recommendations for the care of diabetic individuals need to be more widely implemented. Recommendations targeted specifically to pediatricians may be necessary.

Surveillance for diabetes mellitus--United States, 1980-1989

PROBLEM/CONDITION

In the United States, diabetes mellitus is the most important cause of lower-extremity amputation and end-stage renal disease; the major cause of blindness among working-age adults; a major cause of disability, premature mortality, congenital malformations, perinatal mortality, and health-care costs; and an important risk factor for the development of many other acute and chronic conditions (e.g., diabetic ketoacidosis, ischemic heart disease, stroke). Surveillance data describing diabetes and its complications are critical to increasing recognition of the public health burden of diabetes, formulating health-care policy, identifying high-risk groups, developing strategies to reduce the burden of this disease, and evaluating progress in disease prevention and control.

REPORTING PERIOD COVERED

In this report, data are summarized from CDC's diabetes surveillance system; trends in diabetes and its complications are evaluated by age, sex, and race for the years 1980-1989.

DESCRIPTION OF SYSTEM

CDC has established an ongoing and evolving surveillance system to analyze and compile periodic, representative data on the disease burden of diabetes and its complications in the United States. Data sources currently include vital statistics, the National Health Interview Survey, the National Hospital Discharge Survey, and Medicare claims data for end-stage renal disease.

RESULTS AND INTERPRETATION

In 1989, approximately 6.7 million persons in the United States reported that they had diabetes mellitus, and a similar number probably had this disabling chronic disease without being aware of it. The disease burden of diabetes and its complications is large and is likely to increase as the population grows older. Effective primary, secondary, and tertiary prevention strategies are needed, and these efforts need to be intensified among groups at highest risk, including blacks. Important gaps exist in periodic and representative data for describing the disease burden.

ACTIONS TAKEN

CDC is assisting diabetes control programs in 26 states and one territory. These programs attempt to reduce the burden of diabetes by preventing blindness, lower-extremity amputations, cardiovascular disease, and adverse outcomes of pregnancy among persons with diabetes. Because of important limitations in measuring the burden of diabetes, CDC is exploring sources of surveillance data for blindness, adverse outcomes of pregnancy, and the public health burden of diabetes among minority groups.

Alternative approaches to public health surveillance of IDDM

OBJECTIVE

To assess the appropriateness of national surveillance of IDDM.

RESEARCH DESIGN AND METHODS

We reviewed the structure and function of national disease surveillance, the diverse goals of IDDM surveillance, and prior experience with IDDM as a reportable disease.

RESULTS

Surveillance is the systematic and ongoing collection, analysis, interpretation, and dissemination of data linked to public health action. The potential goals of surveillance of IDDM are to understand the etiology and trends in incidence of IDDM, to measure the burden of IDDM and its complications, and to assess mortality. Problems associated with surveillance of IDDM include underreporting, delayed reporting, and lack of funding.

CONCLUSIONS

To make IDDM a nationally reportable disease is neither warranted nor feasible at this time. Although surveillance is needed to understand diabetes better and for diabetes control, proposed initiatives, such as major expansions of IDDM reporting, should be developed to address specific questions, problems, and needs--still recognizing real-world issues of competing priorities and limited resources.

Diabetes-associated mortality in Native Americans

OBJECTIVE

To describe diabetes-associated mortality among Native Americans.

RESEARCH DESIGN AND METHODS

In this population-based study, we analyzed diabetes-associated mortality data from the IHS and the NCHS. We also examined diabetes data from the 1986 NMFS.

RESULTS

IHS area-specific diabetes mortality rates for 1984-1986 ranged from 10 to 93/100,000, compared with 15/100,000 for the total U.S. population. NCHS data for the same period listed diabetes as the underlying cause of 708 deaths among Native Americans and the contributory cause of 1252 deaths; 63% of the latter deaths were attributable to circulatory diseases. The 1986 NMFS demonstrated that Native American heritage is underreported by 65% on death certificates. Using deaths identified as Native American by NMFS, the age-adjusted mortality rate for diabetes as the underlying cause for Native Americans (96/100,000) was 4.3 times that for whites and two times that for blacks. Where diabetes was a contributory cause of death, the mortality rate for Native Americans (264/100,000) was 3.7 times that for whites and 2.4 times that for blacks.

CONCLUSIONS

The excessive diabetes-associated mortality among Native Americans is consistent with other indicators of the magnitude of the diabetes problem in this population. Further epidemiological research and expanded diabetes control interventions are needed.

Trends in diabetes and diabetic complications, 1980-1987

OBJECTIVE

Although diabetes is a major source of morbidity and mortality in the United States, only recently has a unified national surveillance system begun to monitor trends in diabetes and diabetic complications.

RESEARCH DESIGN AND METHODS

We established a diabetes surveillance system using data for 1980-1987 from vital records, the National Health Interview Survey, the National Hospital Discharge Survey, and the Health Care Financing Administration's records to examine trends in the prevalence and incidence of diabetes, diabetes mortality, hospitalizations, and diabetic complications.

RESULTS

From 1980 through 1987, the number of individuals known to have diabetes increased by 1 million--to 6.82 million. Age-standardized prevalence for diabetes increased 9% during this period, from 25.4 to 27.6/1000 U.S. residents (P = 0.03). The incidence of diabetes increased among women (P = 0.003), particularly among those greater than 65 yr old (P = 0.02). Age-standardized mortality rates (for diabetes as either an underlying or contributing cause) per 100,000 individuals with diabetes declined 12%, from 2350 to 2066. Annual mortality rates from stroke (as an underlying cause and diabetes as a contributing cause) and diabetic ketoacidosis declined 29% (P = 0.003) and 22% (P less than 0.001), respectively. During these 8 yr, hospitalization rates for major CVD and stroke (as the primary diagnoses and diabetes as a secondary diagnosis) increased 34% (P = 0.006) and 38% (P = 0.01), respectively. Also during this period, hospitalization rates increased 21% for diabetic ketoacidosis (P = 0.01) and 29% for lower-extremity amputations (P = 0.06). From 1982 through 1986, treatment for end-stage renal disease related to diabetes increased greater than 10% each year (P less than 0.001). The prevalence of diagnosed diabetes was nearly twice as high in blacks as in whites (P = 0.04). Blacks also had increased rates of lower-extremity amputation (P = 0.02), diabetic ketoacidosis (P less than 0.001), and end-stage renal disease (P = 0.01).

CONCLUSIONS

Diabetes surveillance data will be useful in planning, targeting, and evaluating public health efforts designed to prevent and control diabetes and its complications.

End state renal disease among Native Americans, 1983-86

We used data reported to Medicare from 1983 through 1986 to determine the incidence of end-stage renal disease (ESRD) among Native Americans and Whites in the United States. The 1,075 Native American cases represented an annual incidence, age-adjusted to the White population, of 269 per million, 2.8 times the rate for Whites. Fifty-six percent of Native American cases and 27 percent of the White cases were attributed to diabetes, indicating that ESRD is a major problem. Diabetes control provides the greatest opportunity for prevention.

Incidence of end-stage renal disease in type 2 (non-insulin-dependent) diabetes mellitus in Pima Indians

The incidence of end-stage renal disease was determined in the Pima Indians of the Gila River Indian Community in Arizona, a population with a high prevalence of Type 2 (non-insulin-dependent) diabetes mellitus. Between 1975 and 1986, from a study population of 5059 subjects, end-stage renal disease occurred in 80 persons, 76 (95%) of whom had Type 2 diabetes. A review of the cases with end-stage renal disease indicated that among the diabetic subjects only two cases could be attributed to nondiabetic renal disease; all other cases were attributable to diabetic nephropathy. In diabetic Pima Indians the incidence rate of end-stage renal disease did not change during the study period, was similar in men and women, and was not effected by age at diagnosis of diabetes or by attained age, but did increase significantly with hypertension (p less than 0.05). The incidence of end-stage renal disease attributed to diabetic nephropathy increased from 0 cases/1000 person-years at 0-5 years to 40.8 cases/1000 person-years at greater than or equal to 20 years duration of diabetes. In these subjects with Type 2 diabetes, the incidence rate of end-stage renal disease was similar to that in subjects with Type 1 (insulin-dependent) diabetes who were followed at the Joslin Clinic in Boston, Massachusetts when those with similar duration of diabetes were compared.

The disease-specific benefits and risks of physical activity and exercise

Physical inactivity has been related to the occurrence of coronary heart disease, hypertension, diabetes mellitus, and osteoporosis. The literature was reviewed to determine what is and what is not known about the efficacy and safety of physical activity in each of these conditions. Although there is a transient increase in the risk of sudden cardiac death during vigorous activity, there is mounting evidence that habitual vigorous activity is associated with an overall reduced risk of coronary heart disease. It is unlikely that this association merely reflects the "selection" that results from sick persons who tend to be less active. Several studies suggest that physical activity may be related to the prevention and control of hypertension, diabetes mellitus, and osteoporosis. However, additional research is needed to make explicit the risks and benefits of physical activity in each of these conditions. Finally, future efforts should determine the type, intensity, frequency, and duration of activity required to maximize the benefits and minimize the hazards of physical activity. The public health and clinical significance of these questions requires that they be examined in the most rigorous manner feasible.

A study of neonates' differential responses to three voices, as measured by transcutaneous oxymonitor

123 newborn infants were tested for changes in arterial oxygen status as an index of response to three voices, one of these being the maternal voice. Male infants responded more than female infants to their mother's voice, but female infants showed a higher response to the other female voice and the male voice. Black infants of each sex responded more than white infants to the maternal voice and to the other female voice. White female infants responded more than black female infants to the male voice.

Teachers' generalized expectations of children of divorce

This study examined teachers' generalized expectations for children living with their divorced vs married mothers. Teachers held significantly more negative expectations on 14 expectancy variables for children living with divorced mothers than for children living in traditional two-parent families. Teachers also had more negative expectations for boys living with divorced mothers than for girls from the same family setting, but there were no differences between teachers' expectations of boys and girls from traditional two-parent families. Results are discussed with respect to teachers' generalized expectations possibly becoming self-fulfilling prophecies.

Occult sternal metastasis identified by laminography in patients with chest pain

Six patients with occult sternal metastasis presenting with chest pain, and four with sternal deformity associated with "arthritis" had undergone routine roentgenographic examinations, reported as "normal." Subsequent laminography of the sternum demonstrated lytic lesions confirmed by needle biopsy. Adenocarcinoma of the lung and breast were identified in two each of four patients; myeloma and kidney neoplasms were the primary source of malignancy in the remaining two patients. In widespread malignancy, metastasis to the skeletal chest wall is a well-recognized occurrence. Infrequently, it can be an isolated manifestation of an occult or recurrent malignancy, initially overlooked when routine roentgenograms are read as normal. Although sternal x-rays remain the most important means of diagnosis, in suspected cases of sternal metastasis laminography alone may initially reveal lytic lesions.

Chinese immigrant food habits: a study of the nature and direction of change

THIS STUDY researches the food habits of a randomly selected group of 102 Chinese immi grant mothers who live in two locations in New York City, one predominantly Chinese, namely China town, and the other Queens, a mixed ethnic commun ity. By use of detailed questionnaire and interview, it determines the relationships between traditional food habits before immigration, neighbourhood differences and three time frames since immigration to the United States: under two, two to five and over five years. Significant change has occurred in food habits when comparing those habits practiced before immigration to those practiced in the United States. Of all the items studied, food items showed the greatest changes, parti cularly with respect to meat and dairy products. Some, but not all other food habits changed. The food habits of the respondents in Chinatown, although not com pletely traditional, changed less than the food habits of those living in Queens. Comparing groups by years since immigration, those respondents in the United States fewer than two years ago showed an appreciable change while those in the United States more than five years showed a reversal in some food habits to tradi tional food habits.