Multimodality noninvasive imaging demonstrates in vivo cardiac regeneration after mesenchymal stem cell therapy

OBJECTIVES

The purpose of this study was to test the hypothesis, with noninvasive multimodality imaging, that allogeneic mesenchymal stem cells (MSCs) produce and/or stimulate active cardiac regeneration in vivo after myocardial infarction (MI).

BACKGROUND

Although intramyocardial injection of allogeneic MSCs improves global cardiac function after MI, the mechanism(s) underlying this phenomenon are incompletely understood.

METHODS

We employed magnetic resonance imaging (MRI) and multi-detector computed tomography (MDCT) imaging in MSC-treated pigs (n = 10) and control subjects (n = 12) serially for a 2-month period after anterior MI. A sub-endocardial rim of tissue, demonstrated with MDCT, was assessed for regional contraction with MRI tagging. Rim thickness was also measured on gross pathological specimens, to confirm the findings of the MDCT imaging, and the size of cardiomyocytes was measured in the sub-endocardial rim and the non-infarct zone.

RESULTS

Multi-detector computed tomography demonstrated increasing thickness of sub-endocardial viable myocardium in the infarct zone in MSC-treated animals (1.0 +/- 0.2 mm to 2.0 +/- 0.3 mm, 1 and 8 weeks after MI, respectively, p = 0.028, n = 4) and a corresponding reduction in infarct scar (5.1 +/- 0.5 mm to 3.6 +/- 0.2 mm, p = 0.044). No changes occurred in control subjects (n = 4). Tagging MRI demonstrated time-dependent recovery of active contractility paralleling new tissue appearance. This rim was composed of morphologically normal cardiomyocytes, which were smaller in MSC-treated versus control subjects (11.6 +/- 0.2 mum vs. 12.6 +/- 0.2 mum, p < 0.05).

CONCLUSIONS

With serially obtained MRI and MDCT, we demonstrate in vivo reappearance of myocardial tissue in the MI zone accompanied by time-dependent restoration of contractile function. These data are consistent with a regenerative process, highlight the value of noninvasive multimodality imaging to assess the structural and functional basis for myocardial regenerative strategies, and have potential clinical applications.

Engineering, characterization and in vitro efficacy of the major peanut allergens for use in immunotherapy

BACKGROUND

Numerous strategies have been proposed for the treatment of peanut allergies, but despite the steady advancement in our understanding of atopic immune responses and the increasing number of deaths each year from peanut anaphylaxis, there is still no safe, effective, specific therapy for the peanut-sensitive individual. Immunotherapy would be safer and more effective if the allergens could be altered to reduce their ability to initiate an allergic reaction without altering their ability to desensitize the allergic patient.

METHODS

The cDNA clones for three major peanut allergens, Ara h 1, Ara h 2, and Ara h 3, have been cloned and characterized. The IgE-binding epitopes of each of these allergens have been determined and amino acids critical to each epitope identified. Site-directed mutagenesis of the allergen cDNA clones, followed by recombinant production of the modified allergen, provided the reagents necessary to test our hypothesis that hypoallergenic proteins are effective immunotherapeutic reagents for treating peanut-sensitive patients. Modified peanut allergens were subjected to immunoblot analysis using peanut-positive patient sera IgE, T cell proliferation assays, and tested in a murine model of peanut anaphylaxis.

RESULTS

In general, the modified allergens were poor competitors for binding of peanut-specific IgE when compared to their wild-type counterpart. The modified allergens demonstrated a greatly reduced IgE-binding capacity when individual patient serum IgE was compared to the binding capacity of the wild-type allergens. In addition, while there was considerable variability between patients, the modified allergens retained the ability to stimulate T cell proliferation.

CONCLUSIONS

These modified allergen genes and proteins should provide a safe immunotherapeutic agent for the treatment of peanut allergy.

Donor site morbidity following resection of the fibula

Ten adults were studied two to seven years after resection of a fibula for use as a free vascularised bone graft. Six had no symptoms in the donor leg, four had some aching, weakness or paraesthesia and three had definite weakness of the long toe flexors and extensors. All knees and ankles were clinically and radiologically stable, but the distal fibular remnant was osteoporotic in nine patients. Gait analysis of the donor leg and the contralateral normal leg showed definite differences, which could be attributed to weakness of the deep muscles caused by loss of their normal origin and to the change in load transmission through the fibula.

Retrograde autologous priming for cardiopulmonary bypass: a safe and effective means of decreasing hemodilution and transfusion requirements

OBJECTIVES

The obligatory hemodilution resulting from crystalloid priming of the cardiopulmonary bypass circuit represents a major risk factor for blood transfusion in cardiac operations. We therefore examined whether retrograde autologous priming of the bypass circuit would result in decreased hemodilution and red cell transfusion.

METHODS

Sixty patients having first-time coronary bypass were prospectively randomized to cardiopulmonary bypass with or without retrograde autologous priming. Retrograde autologous priming was performed at the start of bypass by draining crystalloid prime from the arterial and venous lines into a recirculation bag (mean volume withdrawal: 880 +/- 150 ml). Perfusion and anesthetic techniques were otherwise identical for the two groups. The hematocrit value was maintained at a minimum of 16% and 23% during and after cardiopulmonary bypass, respectively, in all patients. Patients were well matched for all preoperative variables, including established transfusion risk factors. Subsequent hemodynamic parameters, pressor requirements, and fluid requirements were equivalent in the two groups.

RESULTS

The lowest hematocrit value during cardiopulmonary bypass was 22% +/- 3% versus 20% +/- 3% in patients subjected to retrograde autologous priming and in control patients, respectively (p = 0.002). One (3%) of 30 patients subjected to retrograde autologous priming had intraoperative transfusion, and seven (23%) of 30 control patients required transfusion during the operation (p = 0.03). The number of patients receiving any homologous red cell transfusions in the two groups during the entire hospitalization was eight of 30 (27%; retrograde autologous priming) versus 16 of 30 (53%; control) (p = 0.03).

CONCLUSIONS

These data suggest that retrograde autologous priming is a safe and effective means of significantly decreasing hemodilution and the number of patients requiring red cell transfusion during cardiac operations.

Cellular and molecular characterization of a major soybean allergen

Soybean proteins share a large number of cross-reacting allergens with other members of the legume family; however, soy-allergic patients rarely react clinically to other members of the legume family. Gly m Bd 30K, an IgE-binding protein with a molecular weight of 30 kD, was identified in soybean extracts by Western IgE-immunoblot analysis. This monomeric allergen was shown to have an N-terminal amino acid sequence and amino acid composition identical to that of the seed 34-kD protein, P34, a thiol protease of the papain family. Electron-microscopic immunolocalization of P34 monoclonal antibodies and IgE binding to sections of soybean seeds showed dense staining throughout the vacuolar bodies, localizing the allergens in protein storage vacuoles of seed cotyledons. We used pooled serum from soybean-sensitive patients to determine the linear IgE-specific epitopes in the 34-kD allergen amino acid sequence. B-cell epitope mapping revealed 10 regions of IgE-binding activity using an overlapping peptide strategy of 15-mers offset by 8 amino acids throughout the P34 sequence. Smaller overlapping peptides, 10-mers offset by 2 amino acids, revealed 16 distinct linear epitopes, 9 of which were mapped to the mature protein. No obvious amino acid sequence motifs could be identified by the smaller IgE-binding epitopes. Using individual patient serum, 5 immunodominant epitopes were identified in this allergen.

The results of ankle arthrodesis

The results are presented of 47 compression arthrodeses of the ankle performed for osteoarthritis in 44 patients. In 26 cases the transverse anterior incision of Charnley had been used and in 21 cases medial and lateral incisions with division of the malleoli. Complications included infection (19%), non-union (14.9%) and malposition requiring a further procedure (8.5%). Three patients (6.4%) eventually had an amputation. Clinical assessment using a standard grading method showed that the functional result was not related to the angle of plantar flexion of the ankle, but was related to the varus/valgus position of the heel, the neutral position being associated with the best results. The anterior approach was more reliable in avoiding varus or valgus of the heel.

Geriatric Elements and Oral Anticoagulant Prescribing in Older Atrial Fibrillation Patients: SAGE-AF

OBJECTIVES

Oral anticoagulants are the cornerstone of stroke prevention in high-risk patients with atrial fibrillation (AF). Geriatric elements, such as cognitive impairment and frailty, commonly occur in these patients and are often cited as reasons for not prescribing oral anticoagulants. We sought to systematically assess geriatric impairments in patients with AF and determine whether they were associated with oral anticoagulant prescribing.

DESIGN

Cross-sectional analysis of baseline data from the ongoing Systematic Assessment of Geriatric Elements in Atrial Fibrillation (SAGE-AF) prospective cohort study.

SETTING

Multicenter study with site locations in Massachusetts and Georgia that recruited participants from cardiology, electrophysiology, and primary care clinics from 2016 to 2018.

PARTICIPANTS

Participants with AF age 65 years or older, CHA₂ DS₂ -VASc (congestive heart failure; hypertension; aged ≥75 y [doubled]; diabetes mellitus; prior stroke, transient ischemic attack, or thromboembolism [doubled]; vascular disease; age 65-74; female sex) score of 2 or higher, and no oral anticoagulant contraindications (n = 1244).

MEASUREMENTS

A six-component geriatric assessment included validated measures of frailty, cognitive function, social support, depressive symptoms, vision, and hearing. Oral anticoagulant use was abstracted from the medical record.

RESULTS

A total of 1244 participants (mean age = 76 y; 49% female; 85% white) were enrolled; 42% were cognitively impaired, 14% frail, 53% pre-frail, 12% socially isolated, and 29% had depressive symptoms. Oral anticoagulants were prescribed to 86% of the cohort. Oral anticoagulant prescribing did not vary according to any of the geriatric elements (adjusted odds ratios [ORs] for oral anticoagulant prescribing and cognitive impairment: OR = .75; 95% confidence interval [CI] = .51-1.09; frail OR = .69; 95% CI = .35-1.36; social isolation OR = .90; 95% CI = .52-1.54; depression OR = .79; 95% CI = .49-1.27; visual impairment OR = .98; 95% CI = .65-1.48; and hearing impairment OR = 1.05; 95% CI = .71-1.54).

CONCLUSION

Geriatric impairments, particularly cognitive impairment and frailty, were common in our cohort, but treatment with oral anticoagulants did not differ by impairment status. These geriatric impairments are commonly cited as reasons for not prescribing oral anticoagulants, suggesting that prescribers may either be unaware or deliberately ignoring the presence of these factors in clinical settings. J Am Geriatr Soc 68:147-154, 2019.

Long-term results of total ankle replacement

The results are reported of 19 total ankle replacements in 18 patients with rheumatoid or other inflammatory arthritis. After a mean follow-up period of 54.4 months (minimum, 24 months), three arthroplasties had failed, all because of loosening. Although all of the remaining patients were improved in terms of pain and function, there was radiographic evidence of loosening in a further eight patients. Indications for the operation are discussed.

Isolation and characterization of a clone encoding a major allergen (Bla g Bd90K) involved in IgE-mediated cockroach hypersensitivity

Previous studies have established that atopic individuals living in cockroach-infested housing become sensitized to cockroach aeroallergens and produce IgE antibodies to a variety of proteins. We describe the isolation of a complementary DNA clone from an expression library, constructed with messenger RNA from German (Blattella germanica) cockroaches, which encodes a major allergen involved in mediating cockroach hypersensitivity. Approximately 0.2% of the clones from a lambda ZAP XR cDNA library bound IgE from a patient with cockroach sensitivity. A randomly selected subset of these clones revealed that they were either different isolates of the same gene or members of a closely related gene family. One of the largest clones (a 4 kb insert) from this subset, Bla g Bd90K hybridized to a single mRNA of approximately the same size. DNA sequence analysis showed that this gene consisted of seven 576 bp tandem repeats with a short unique region at either end. No significant sequence homologies were found between the cockroach clone and any other gene reported in the GenBank database. Serum from 17 of 22 (77%) patients with cockroach hypersensitivity identified IgE-binding recombinant protein expressed from clone Bla g Bd90K in Escherichia coli XL-Blue cells as determined by sodium dodecylsulfate-polyacrylamide gel electrophoresis/immunoblot analysis. This recombinant protein migrates with a molecular weight (90 kd) apparently similar to one identified in whole body extracts. We have identified and isolated a cDNA that encodes a major cockroach allergen (Bla g Bd90K) present in German cockroaches.

Cross-reactivity of IgE-binding components between boiled Atlantic shrimp and German cockroach

IgE-antibody reactivity to boiled Atlantic shrimp (Pandalus borealis) and German cockroach (Blattella germanica) of sera from 89 patients, sensitive to one or the other, was investigated with an enzymatic immunoassay for specific IgE detection (CAP-FEIA System, Pharmacia, Sweden). IgE serum levels to both antishrimp and anticockroach allergens were found to be positive in 76 of the 89 (85.4%) tested sera. A positive anticockroach IgE was very rare in the absence of detectable antishrimp IgE (five of 89 sera). Linear regression analysis on antishrimp and anti-German cockroach IgE levels-log plot revealed a correlation coefficient (r) of 0.73. Inhibition experiments showed that boiled Atlantic shrimp extract inhibited CAP with German cockroach, and vice versa. Immunoblotting showed the strongest IgE binding for both allergenic extracts between 30 and 43 kDa. By blot inhibition, the binding capacity of German cockroach was totally abolished by Atlantic shrimp extract, while German cockroach extract only partially IgE binding to Atlantic shrimp. Cross-reactivity exists between shrimp, an important food allergen, and German cockroach, which has an increasing role in allergic asthma. It could be important to determine the clinical significance of cross-allergy to both allergens, in which exposures occur in different ways.

cDNA clones of Onchocerca volvulus low molecular weight antigens provide immunologically specific diagnostic probes

We report here a panel of cDNA clones from Onchocerca volvulus which were isolated on the basis of being uniquely recognised by onchocerciasis sera and not by sera from patients infected with the major lymphatic filarial nematode parasite Wuchereria bancrofti. Over 90% of O. volvulus recombinants from a primary screen were found to cross-react with lymphatic filariasis sera and were discarded. The subset of specific clones, selected with pooled sera, was then screened with panels of individual patient sera. Individual onchocerciasis cases showed a highly heterogeneous pattern of recognition of recombinant peptides, but several clones were identified which could be combined in a cocktail of antigenic epitopes to successfully detect all infected cases in the study. All these clones encode low molecular weight proteins of the parasite, confirming earlier reports that antigens of this size class show greater species specificity. Several clones encode proteins of 20-23 kDa, the same molecular weight range as the major surface protein of adult worms. The two most commonly recognised clones, Ov22/31M and Ov20/36M were subcloned into the vector pNGS 8 which produces fusion proteins attached to a polyasparagine leader. The fusion peptides of both Ov22/31M and Ov20/36M were soluble and easily purified by gel filtration. Purified fusion protein was used in ELISA to assess reactivity of infected patients giving 90% sensitivity with 100% specificity.

Onchocerca volvulus: characterization of an immunodominant hypodermal antigen present in adult and larval parasites

Biochemical and immunological data suggest that a relatively limited number of polypeptide antigens of viable Onchocerca volvulus-infective larvae are available to be recognized by the host's immune system. A partial cDNA clone encoding one such antigen, designated lambda RAL-2, was isolated by screening an expression cDNA library with antisera raised against viable O. volvulus L3. The antigen encoded by this clone was subsequently found to be immunogenic in the majority of individuals exposed to O. volvulus. In the present study, the native antigen corresponding to lambda RAL-2 (Ov17) has been characterized. Immunolocalization and in situ hybridization techniques have been used to localize Ov17 in adult and larval stages of the parasite. In adult females, Ov17 was localized primarily in the hypodermis. Ov17 was accessible to surface labeling reagents in viable adult parasites. Full-length cDNA clones encoding Ov17 suggested that the nascent protein contains a putative leader sequence, which is almost immediately followed by a polyglutamine tract. Analysis of antibody reactivity to recombinant proteins containing and lacking the polyglutamine tract demonstrated that this structure was not a significant B cell epitope in individuals exposed to O. volvulus.

MAST system: a new condensed cardiopulmonary bypass circuit for adult cardiac surgery

There have been many refinements in cardiopulmonary bypass (CPB) techniques over the past few decades specific to design, materials and function. Despite these improvements, use of the standard length circuit tubing and pump oxygenator alter cellular, biochemical and rheological properties by inducing a systemic inflammatory response, persisting well into the early postoperative phase. We have designed a new condensed CPB circuit, the MAST system, where the oxygenator and the pumps are brought closer to the operating table (within 30 inches) with the help of a series of telescopic swivel steel poles to which they are attached. The control console is retained at the usual remote location of 2ft behind the MAST system. This configuration accomplishes a decrease in tubing length, priming volume and blood circulatory time within the extracorporeal circuit. Early experience of a hundred consecutive cases utilizing the MAST CPB system is presented along with a comparative analysis of prime volume, hemodilution and transfusion parameters of MAST system vs the low prime system, which is another newly developed CPB circuit utilizing a pediatric oxygenator to reduce prime volume and hemodilution.

Neuropsychological test performance of former American football players

BACKGROUND

Patterns of cognitive impairment in former American football players are uncertain because objective neuropsychological data are lacking. This study characterized the neuropsychological test performance of former college and professional football players.

METHODS

One hundred seventy male former football players (n=111 professional, n=59 college; 45-74 years) completed a neuropsychological test battery. Raw scores were converted to T-scores using age, sex, and education-adjusted normative data. A T-score ≤ 35 defined impairment. A domain was impaired if 2+ scores fell in the impaired range except for the language and visuospatial domains due to the limited number of tests.

RESULTS

Most football players had subjective cognitive concerns. On testing, rates of impairments were greatest for memory (21.2% two tests impaired), especially for recall of unstructured (44.7%) versus structured verbal stimuli (18.8%); 51.8% had one test impaired. 7.1% evidenced impaired executive functions; however, 20.6% had impaired Trail Making Test B. 12.1% evidenced impairments in the attention, visual scanning, and psychomotor speed domain with frequent impairments on Trail Making Test A (18.8%). Other common impairments were on measures of language (i.e., Multilingual Naming Test [21.2%], Animal Fluency [17.1%]) and working memory (Number Span Backward [14.7%]). Impairments on our tasks of visuospatial functions were infrequent.

CONCLUSIONS

In this sample of former football players (most of whom had subjective cognitive concerns), there were diffuse impairments on neuropsychological testing with verbal memory being the most frequently impaired domain.

Physical, cognitive, and psychosocial conditions in relation to anticoagulation satisfaction among elderly adults with atrial fibrillation: The SAGE-AF study

BACKGROUND

Successful anticoagulation is critical for stroke prevention in adults with atrial fibrillation (AF). Anticoagulation satisfaction is a key indicator of treatment success. While physical, cognitive, and psychosocial limitations are common in elderly AF patients, their associations with anticoagulation satisfaction are unknown.

OBJECTIVE

Examine whether anticoagulation satisfaction differs among AF patients with and without physical, cognitive, and psychosocial conditions.

METHODS

The study comprised AF patients greater than or equal to 65 years old who were prescribed an oral anticoagulant (warfarin 57%; direct oral anticoagulant [DOAC] 43%). Frailty, cognitive function, social support, depressive symptoms, vision, hearing, and anxiety were assessed using validated measures. Anticoagulation satisfaction was measured using the anticlot treatment scale.

RESULTS

Participants (n = 1037, 50% female) were on average 76 years old. The following conditions were prevalent: frailty (14%), cognitive impairment (42%), social isolation (13%), vision impairment (35%), hearing impairment (36%), depression (29%), and anxiety (24%). Average anticlot treatment burden scale was 55 out of 60 (lower burden scales indicating higher perceived burden). Patients with high perceived burden were older, more likely to be female, and receive warfarin. After adjusting for confounders, visual impairment (adjusted odds ratio [95% confidence interval]: 1.7 [1.2-2.4]), depressive symptoms (2.4 [1.6-3.7]), and anxiety (1.8 [1.2-2.7]) were significantly associated with high perceived burden. Different conditions were associated with high perceived burden in warfarin vs DOAC users.

CONCLUSION

Physical, cognitive, and psychosocial limitations are prevalent and associated with high perceived anticoagulation burden among elderly AF adults. These conditions merit consideration in anticoagulation prescribing.

Geographic variability in potentially discretionary red blood cell transfusions after coronary artery bypass graft surgery

OBJECTIVE

A number of established regional quality improvement collaboratives have partnered to assess and improve care across their regions under the umbrella of the Cardiac Surgery Quality Improvement (IMPROVE) Network. The first effort of the IMPROVE Network has been to assess regional differences in potentially discretionary transfusions (<3 units red blood cells [RBCs]).

METHODS

We examined 11,200 patients undergoing isolated nonemergent coronary artery bypass graft surgery across 56 medical centers in 4 IMPROVE Network regions between January 2008 and June 2012. Each center submitted the most recent 200 patients who received 0, 1, or 2 units of RBC transfusion during the index admission. Patient and disease characteristics, intraoperative practices, and percentage of patients receiving RBC transfusions were collected. Region-specific transfusion rates were calculated after adjusting for pre- and intraoperative factors among region-specific centers.

RESULTS

There were small but significant differences in patient case mix across regions. RBC transfusions of 1 or 2 units occurred among 25.2% of coronary artery bypass graft procedures (2826 out of 11,200). Significant variation in the number of RBC units used existed across regions (no units, 74.8% [min-max, 70.0%-84.1%], 1 unit, 9.7% [min-max, 5.1%-11.8%], 2 units, 15.5% [min-max, 9.1%-18.2%]; P < .001). Variation in overall transfusion rates remained after adjustment (9.1%-31.7%; P < .001).

CONCLUSIONS

Delivery of small volumes of RBC transfusions was common, yet varied across geographic regions. These data suggest that differences in regional practice environments, including transfusion triggers and anemia management, may contribute to variability in RBC transfusion rates.

Radial reconstruction in segmental defects of both forearm bones

Seven patients with segmental defects of both bones of the forearm had reconstruction operations using a vascularised fibular graft to bridge the radius. Reasonable forearm rotation was preserved with full elbow movements and satisfactory hand function.

Food allergens

A number of advances in the scientific knowledge concerning adverse food reactions have been made in the past few years. Understanding about the nature of the food allergen itself, the molecular characterization of the epitopes on these allergens, the pathophysiology of the clinical reaction, and the diagnostic methods have all been significantly enhanced.