Analysis of the regenerative capacity of human serum exosomes after a simple multistep separation from lipoproteins

Due to the abundance of lipoproteins in blood, it is challenging to characterize the biological functions and components of blood-derived extracellular vesicles. The aim of this study was to develop a multiple-step purification protocol to separate serum exosomes from serum proteins and lipoproteins and assess their regenerative potential. Exosomes were isolated by concentrating them in human serum using ultracentrifugation (UC), followed sequentially by density gradient (DG) UC and size exclusion chromatography (SEC). Purity and characterization were assessed by western blots, Lipoprint®, enzyme-linked immunosorbent assay, electron microscopy, mass spectrometry, and nanoparticle tracking analysis. Functionality was assessed by cell proliferation analysis and with an in vivo subcutaneous angiogenesis model. SEC alone isolated nano-sized vesicles possessing vesicle markers TSG101 and CD9, but there was a substantial presence of apolipoprotein B, predominantly derived from very-low- and intermediate-density lipoprotein particles. This was reduced to an undetectable level using the combined UC DG SEC approach. Mass spectrometry identified 224 proteins in UC DG SEC isolates relative to the 135 from SEC, with considerable increases in exosome-related proteins and reductions in lipoproteins. A consistent but limited increase in human dermal fibroblast proliferation and evidence of neovascularization enhancement were observed after exposure to UC DG SEC exosomes. An UC DG SEC purification protocol considerably improved the removal of lipoproteins during isolation of serum exosomes. The purified exosomes stimulated cell proliferation and potentially increased an in vivo angiogenic response. This multistep purification allows for more accurate identification of serum exosome functional activity and composition.

Minimal information for studies of extracellular vesicles 2018 (MISEV2018): a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles ("MISEV") guidelines for the field in 2014. We now update these "MISEV2014" guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points.

Palmitic acid feeding increases ceramide supply in association with increased milk yield, circulating nonesterified fatty acids, and adipose tissue responsiveness to a glucose challenge

Reduced insulin action is a key adaptation that facilitates glucose partitioning to the mammary gland for milk synthesis and enhances adipose tissue lipolysis during early lactation. The progressive recovery of insulin sensitivity as cows advance toward late lactation is accompanied by reductions in circulating nonesterified fatty acids (NEFA) and milk yield. Because palmitic acid can promote insulin resistance in monogastrics through sphingolipid ceramide-dependent mechanisms, palmitic acid (C16:0) feeding may enhance milk production by restoring homeorhetic responses. We hypothesized that feeding C16:0 to mid-lactation cows would enhance ceramide supply and ceramide would be positively associated with milk yield. Twenty multiparous mid-lactation Holstein cows were enrolled in a study consisting of a 5-d covariate, 49-d treatment, and 14-d posttreatment period. All cows were randomly assigned to a sorghum silage-based diet containing no supplemental fat (control; n=10; 138±45 d in milk) or C16:0 at 4% of ration dry matter (PALM; 98% C16:0; n=10; 136±44 d in milk). Blood and milk were collected at routine intervals. Liver and skeletal muscle tissue were biopsied at d 47 of treatment. Intravenous glucose tolerance tests (300mg/kg of body weight) were performed at d -1, 24, and 49 relative to start of treatment. The plasma and tissue concentrations of ceramide and glycosylated ceramide were determined using liquid chromatography coupled with tandem mass spectrometry. Data were analyzed as repeated measures using a mixed model with fixed effects of treatment and time, and milk yield served as a covariate. The PALM treatment increased milk yield, energy-corrected milk, and milk fat yield. The most abundant plasma and tissue sphingolipids detected were C24:0-ceramide, C24:0-monohexosylceramide (GlcCer), and C16:0-lactosylceramide. Plasma concentrations of total ceramide and GlcCer decreased as lactation advanced, and ceramide and GlcCer were elevated in cows fed PALM. Palmitic acid feeding increased hepatic ceramide levels, a response not observed in skeletal muscle tissue. Plasma ceramides (e.g., C24:0-ceramide) were positively correlated with plasma NEFA and milk yield, and positively correlated with NEFA levels following a glucose challenge. Our data demonstrate a remodeled plasma and hepatic sphingolipidome in mid-lactation dairy cows fed PALM. The potential involvement in ceramide in homeorhetic nutrient partitioning to support lactation requires further consideration.

Transport of Mechanically Ventilated Patients in the Prone Position

OBJECTIVE

We present seven cases of patients with severe respiratory failure refractory to conventional ventilation who were safely transported in the prone position.

METHODS

We describe all cases of patients transported by a regional critical care network in the prone position from January 2010-June 2015. All patients were mechanically ventilated for respiratory failure and transported by specialized nonphysician critical care teams. Utilizing direct medical oversight and real-time technical support from the clinical department, each patient underwent a thorough bedside evaluation, transport ventilator trial, and transfer to a transport stretcher either with the endotracheal tube secured by an anesthesia pillow or overhanging the stretcher.

RESULTS

Seven patients with acute respiratory distress syndrome were transported in the prone position. Four were female (57%), with a median weight of 78 kg (range 58-131) and median age of 53 years (range 37-78). Initial vital signs demonstrated a median oxygen saturation of 94% (range 90-97%) supported with a FiO2 of 100% for all patients with a median positive end-expiratory pressure (PEEP) of 16 (range 14-20). Seven patients were transported, six by helicopter and one transported by ground ambulance. The median transport time was 36 minutes (IQR 19, 51). There were no deaths or major incidents (tube dislodgement or line displacement) during patient transport.

CONCLUSION

The transport of mechanically ventilated patients with respiratory failure in the prone position is feasible and safe, with minimal complications identified in this case series.

Clinical agreement between automated and calculated ultrasound measurements of bladder volume

Non-invasive urine volume measurement is an important tool in the management of dysfunctional and neuropathic bladders in children. Ultrasound imaging devices have been used for many years for this purpose. An automated scanner (Bladderscan) is now available and has been recommended by a number of authors, but there is conflicting evidence in the literature regarding the accuracy and appropriate clinical application of the device. We aimed to assess the level of clinical agreement between the two methods. 36 urine volume measurements were made on 11 children using both instruments. Although there was a good correlation between the methods (r=0.97), the clinical agreement was poor (limits of agreement +/-77 ml). 13 voided volumes were directly measured and compared with the difference between pre- and post-void ultrasound measurements. The systematic errors were small but the mean absolute errors were 54 ml and 23 ml, respectively, for the automated and ultrasound imaging methods. If used correctly, ultrasound imaging provides more accurate results and can compete with the cost, convenience and ease of use of the automated method. Low cost, highly portable ultrasound imaging devices are now available and should be used in preference to the Bladderscan.

Breaking bad news--development of a hospital-based training workshop

The skills required to break bad news have been written about extensively and are taught in medical schools. Recent initiatives have concentrated on improving the skills of doctors and nurses in senior positions, who act as role models for their junior colleagues. A multiprofessional learning situation can be a threatening environment, in which colleagues may worry about exposing some of the weaknesses in their knowledge and skills regarding communication with patients. We describe the initiation, running, and evaluation of successful training workshops on breaking bad news in a large British district hospital.

Waiting lists. On a knife edge

Achieving the government's waiting list targets relies heavily on the willingness of theatre staff to do overtime. A survey of acute trusts in England found that more than three-quarters were having difficulty recruiting staff. A third were using local pay incentives, including double time for waiting list initiative work and bonus schemes. Theatre management needs a more strategic approach.

Immune hyperactivation of HIV-1-infected T cells mediated by Tat and the CD28 pathway

Human immunodeficiency virus-type 1 (HIV-1) infection is characterized by a chronic state of immune hyperactivation in patients. Infection of human peripheral blood lymphocytes with HIV-1 in vitro resulted in increased interleukin-2 (IL-2) secretion in response to T cell activation via the CD3 and CD28 receptors. Expression of the HIV-1 transactivator Tat recapitulated this phenotype and was associated with increased IL-2 secretion in response to costimulation with CD3 plus CD28. IL-2 superinduction by Tat occurred at the transcriptional level, was mediated by the CD28-responsive element in the IL-2 promoter, and was exclusively dependent on the 29 amino acids encoded by the second exon of Tat.

Group therapeutic factors on an alcohol in-patient unit

Seventy consecutive patients admitted to an alcohol unit were given a modified version of Yalom's therapeutic factor questionnaire at various points during the therapeutic programme. This programme consists of a two-week introductory programme, followed by a treatment programme, which includes psychodynamic groups, life-history reviews and intensive cognitive-therapy sessions. Internal agreement of ranking order of therapeutic factors was high among all patients and was independent of time spent in group therapy. Patients valued most an existential factor (which embraces concepts of personal responsibility and isolation), self-understanding and cohesiveness; they least valued guidance and identification. Therapists also completed the questionnaire: their ranking of therapeutic factors correlated highly with that of patients, but they ranked an existential factor much lower.

Inguinal herniation justifies sigmoidoscopy

Controversy exists concerning the association of inguinal hernia and colonic carcinoma and, more specifically, whether the development of an inguinal hernia justifies sigmoidoscopy. To study the role of endoscopic screening in cases of inguinal hernia, we prospectively evaluated 464 patients with inguinal hernia over a 54-month period with flexible sigmoidoscopy. Each patient was over the age of 40 and male. Sigmoidoscopy documented polyps (97 patients, 21 percent) and carcinoma (22 patients, 5 percent). Multiple neoplasms were observed in 6 percent (7 of 119 patients). Occult blood was detected in the fecal specimens of 8 percent of the total group of patients, but in only 13 percent of the patients with polyps or carcinomas. A normal examination occurred in only 38 percent of the total group. By using the presence of an inguinal hernia in patients older than 40 years of age as an indication for sigmoidoscopy, we found that more than one of every four patients had an asymptomatic, concurrent malignant or premalignant colonic lesion. Flexible sigmoidoscopy should be used for screening colonic neoplasms in patients with inguinal hernia.

Isolation and identification of Listeria monocytogenes in dairy products

After an outbreak of listeriosis in Massachusetts in 1983, the ability of Listeria monocytogenes to survive in raw and pasteurized milk was investigated. An enrichment broth (EB) containing acriflavine, nalidixic acid, and cycloheximide was used to eliminate overgrowth of the culture by competing organisms, and a modification of McBride's agar (MMA) was used as the isolation medium. The culture was incubated 24 h at 30 degrees C. To isolate Listeria from soft cheese, the incubation period was lengthened to 1 week, and the EB culture was streaked to MMA at 1 and 7 days. Physical and biochemical patterns, the CAMP test, serological tests, and mouse pathogenicity studies were helpful in determining the identity of L. monocytogenes.

Pathogenicity test for Listeria monocytogenes using immunocompromised mice

The lethality of Listeria isolates was determined with normal adult mice and mice that were immunocompromised by treatment with 20 mg of carrageenan per kg. The mean 50% lethal doses (LD50s) of the pathogenic isolates were significantly lower (alpha = 0.05) in the immunocompromised mice than in the untreated mice, with an average reduction of 5.8 log10 units. In contrast, the mean LD50s of the nonpathogenic isolates were lower in the immunocompromised mice by an average of only 0.4 log10 unit, a difference that was not significant (alpha = 0.05). When immunocompromised mice were used, the LD50s of pathogenic Listeria monocytogenes isolates were lower than those of nonpathogenic L. innocua and L. seeligeri isolates by greater than or equal to 6 log10 units and lower than those of nonpathogenic L. ivanovii isolates by greater than or equal to 4 log10 units. Pathogenic L. monocytogenes isolates could be distinguished from nonpathogenic isolates by their ability to cause deaths in immunocompromised mice in 3 days at a dose of approximately 10(4) CFU per mouse. An alternative procedure using iron-overloaded mice failed to effectively differentiate pathogenic Listeria isolates.

Listeria monocytogenes in Raw Milk: Detection, Incidence, and Pathogenicity

To determine the incidence of Listeria monocytogenes in raw milk, an isolation method was evaluated and used to analyze milk from three areas of the United States. The incidence varied by area from 0% in California to 7% in Massachusetts, with an overall incidence of 4.2%. The highest incidence found in any area during a single sampling period was 12% in Massachusetts in March 1985. During that same sampling, the incidence for all Listeria species was 26%. Of the 27 L. monocytogenes strains isolated during the survey, 25 were pathogenic in adult mice. One of three Listeria ivanovii isolated was pathogenic. No other isolates demonstrated pathogenicity.

A comparison of the antidepressant action of citalopram and amitriptyline

The response of patients with major depressive illness to citalopram of amitriptyline was compared in a double-blind multi-centre trial. No differences in efficacy were observed, but citalopram had less hypnotic effect, and a remarkably lower profile of side-effects.

Suppression of post-vasectomy cytotoxic sperm antibody formation in rats by a short-term pretreatment with cyclosporine

The effect of a short pulse therapy with cyclosporine on the production of vasectomy-induced cytotoxic sperm antibodies was studied in Lewis rats. Cyclosporine at a dose of 10 mg/kg was administered once daily for 7 days before and 7 days after vasectomy (group A), for 7 days before vasectomy (group B), and for 7 days after vasectomy (group C). Ten rats were studied in each group for a period of 5 weeks. Ten rats were vasectomized and untreated with cyclosporine (group U). All animals in this group developed high titers of cytotoxic sperm antibodies at the end of the first week after vasectomy (primary antibody response). In contrast, all the treated rats of groups A, B, and C had a normal range of sperm antibody titers. By the third week, six of nine rats in the post-treated group C had significant cytotoxic sperm antibody titers, while the other groups had normal antibody titers. In the fourth week, all the rats of groups A and B continued to have normal sperm antibody titers of less than or equal to 16, while most animals in groups C (78%) and U (63%) had significant cytotoxic sperm antibody titers. It is concluded that prevasectomy treatment with cyclosporine may significantly reduce or delay the production of cytotoxic sperm antibodies in Lewis rats.

Comparison of methods for isolating Campylobacter jejuni from raw milk

The method of Doyle and Roman (Appl. Environ. Microbiol. 43:1343-1353, 1982) was compared with that of Lovett et al. (Appl. Environ. Microbiol. 46:459-462, 1983) for the ability to recover Campylobacter jejuni strains inoculated into raw milk at a concentration of less than 1 cell per g. The method of Lovett et al. gave significantly greater recovery proportions.

Physician attitudes toward confidential care for adolescents

We examined factors that determine whether pediatricians will grant confidential care to adolescents. Through four vignettes, in which adolescents of different ages and maturity requested confidential care, we assessed the willingness of physicians to give such care for four problems: request for contraceptive, diagnosis of gonorrhea, intrauterine device found incidentally on x-ray study, and illicit drug use. A random sample of 932 physicians responded to the vignettes. Overall, physicians agreed to give confidential care to adolescents in 75% of the vignettes. They were more likely to give confidentiality in cases involving sexual activity. They supported confidential care for 87% of patients requesting contraceptives, but for only 54% reporting illicit drug use. The proportion of physicians supporting confidentiality increased with age and maturity of the minors. Seventeen-year-old mature adolescents seeking contraceptives were given confidentiality by 97% of physicians. Thus physician responses to vignettes indicated that they strongly support confidential care for adolescents as represented in the clinical vignettes.

Detection of Escherichia coli enterotoxins by using mouse adrenal cell and suckling mouse assays: collaborative study

The ability of 10 Escherichia coli strains to produce heat-stable enterotoxin (ST) and heat-labile enterotoxin (LT) was determined by 8 analysts in a collaborative study. The suckling mouse model and the mouse adrenal cell line (Y-1) tests were used to detect ST and LT, respectively. Cultures for assay were grown 24 h in casamino acid-yeast extract-trace salts broth at 37 degrees C in a shaker incubator at 250 rpm. Cell-free culture broth prepared by centrifugation and filtration was divided into 2 portions: One was heated for 30 min and used both for ST assay and as a heated control for LT assay; the other was used unheated for LT assay. Results were expressed as positive for ST, positive for LT, positive for ST and LT, or negative for both ST and LT; percent of correct estimates was calculated for each culture for each analyst. At the 95% confidence interval, the overall correct results were 96.3 +/- 2.9 and 95.0 +/- 3.4% for ST and LT, respectively. The test performances thus were satisfactory for detecting ST and LT produced in vitro by E. coli. The method has been adopted official first action.

A comparison of clinical course with blood group antigen testing by specific red cell adherence and immunoperoxidase in ureteral and renal pelvic tumors

Specimens of transitional cell carcinoma of the ureter and renal pelvis from 20 patients were tested for blood group antigenicity using immunoperoxidase and specific red cell adherence methods. The results of antigen testing were correlated with tumor stage and grade as well as the subsequent clinical course of the patients. The specific red cell adherence test was negative in 80 per cent and the immunoperoxidase test was negative in 40 per cent of all tumors. Of the 4 patients with positive specific red cell adherence tests 3 had high grade (II to III), invasive tumors as did 7 of 12 with tumors that were positive by immunoperoxidase testing. Blood group antigen testing did not prove helpful in predicting the clinical course of our patients. In addition, a careful review of previously published data does not support the conclusion that blood group antigen testing is a valuable predictor of upper tract tumor aggressiveness.

Isolation of Campylobacter jejuni from raw milk

Campylobacter jejuni was isolated from raw milk by a method that can routinely detect less than or equal to 1 organism per ml. This procedure was used in a survey of 195 separate farms and showed a 1.5% incidence of C. jejuni in milk from bulk tanks.

Effect of temperature, duration of incubation, and pH of enrichment culture on the recovery of Campylobacter jejuni from eviscerated market chickens

To establish an enrichment system of high efficiency for recovery of Campylobacter jejuni from market chickens, the effects of the temperature, duration of incubation, and pH of the enrichment culture on the isolation of the bacterium were evaluated. Whole chickens or chicken parts in plastic bags were individually rinsed, and the washings filtered through cheesecloth. The cells were separated from the washings by centrifugation, and the pellet was inoculated into 100 mL of enrichment broth. Isolation of C. jejuni from poultry samples was significantly increased by incubating these samples in an enrichment medium at 42 degrees C as opposed to 35 degrees C; for 48 h as opposed to 24 h or 72 h; and at pH 7.0 as opposed to pH 6.0, 6.5, 7.5, or 8.0.

Thermal inactivation of Yersinia enterocolitica in milk

Three strains of Yersinia enterocolitica isolated from milk had D values at 62.8 degrees C from 0.24 to 0.96 min and z values of 5.11 to 5.78 degrees C. Since the pasteurization processes for dairy products recommended by the Food and Drug Administration are adequate to destroy large concentrations of these organisms, Y. enterocolitica in pasteurized milk probably results from substandard processing or recontamination after pasteurization.

Incidence of Campylobacter jejuni in fresh eviscerated whole market chickens

A total of 100 fresh eviscerated whole market chickens, purchased one per week over a 5-week period from each of 20 different food stores in the Ontario and Ohio regions, were examined for the presence of Campylobacter jejuni. The microorganism was recovered from 62 and 54% of the chickens in Ontario and Ohio, respectively.

Enterotoxin production and thermal resistance of Yersinia enterocolitica in milk

Three of 36 raw milk isolates of Yersinia enterocolitica produced enterotoxin in milk at 25 degrees C, but not at 4 degrees C. No strain tested could survive pasteurization.

Travel for primary care: expectation and performance in a rural setting

Data and findings are presented pertaining to the expressed travel limits for general medical care of a rural population and the degree to which their observed travel behavior reflects these limits. Considerable variation in expressed reasonable and maximum travel distances and times was observed among respondents in a countywide cross-section sample of the resident population in western Maine. A substantial proportion of the respondents' visits for general medical care exceeds their reasonable travel limits and some visits exceed the travel limits they considered maximal. Additionally, a comparison of expectations from this study with those of a similar population in another section of the county reveals significant differences. The findings suggest that health planning could be considerably enhanced by a better understanding of patient preferences for medical care travel behavior, the origins of these preferences, and their relationship to the use of available medical care opportunities. This is particularly true if stated goals of incorporating patient preferences into the health planning process are to be realized.

Successful re-treatment with cis-dichlorodiammineplatinum(II) after apparent allergic reactions

Allergic or anaphylactic-like reactions have been reported with cis-dichlorodiammineplatinum(II) (CDDP) administration. We have seen two reactions among 50 patients treated in a phase II trial of CDDP. Both patients were successfully rechallenged after diphenhydramine pretreatment, and therapy was continued. In vivo and in vitro studies performed in one patient included negative skin tests, negative histamine release assay, negative lymphocyte stimulation studies, and normal total serum IgE. We conclude that some apparent allergic reactions occurring with CDDP may have a non-allergic etiology, and treatment may be successfully continued in selected patients.

Patulin Production by Species of Aspergillus and Penicillium at 1.7, 7.2, and 12.8 C

Two strains each of Aspergillus clavatus (NRRL 1980 and ATCC 9599), Penicillium claviforme (NRRL 1001 and 1002), Penicillium expansum (FM 1071 and NRRL 973), and Penicillium patulum (ATCC 24550 and FM 1172); and one strain of Penicillium griseofulvum (NRRL 2300) were inoculated into potato-dextrose broth and incubated at 1.7, 7.2, and 12.8 C for 110, 84, and 55 days, respectively. All cultures grew at all temperatures. Patulin production by P. griseofulvum and P. claviforme , NRRL 1001, was limited or inhibited at 1.7 C, whereas at 7.2 C only P. griseofulvum , NRRL 2300, failed to produce toxin. Patulin was produced at 12.8 C by all nine cultures.

Trimming as a means of removing patulin from fungus-rotted apples

Penicillium expansum 1071, 1172, NRLL 973, and Penicillium patulum ATCC 24550 were inoculated into Red Delicious, Golden Delicious, and McIntosh apples. The decayed tissue was trimmed from the sound tissue, each fraction was weighed, and the patulin concentration in the juice was assayed by thin layer chromatography. The quantity of patulin in the whole apples and in decayed tissues was calculated and these values were used to determine the percentage of total patulin removed by trimming. The patulin content ranged from 140 to 4880 mug/apple. Trimming removed 93-99% of the total patulin, regardless of incubation temperature, fungus strain, or apple variety. Trimming of defective tissue from fungus-rotted apples could substantially reduce the patulin concentration.