Intelligent digital tools for screening of brain connectivity and dementia risk estimation in people affected by mild cognitive impairment: the AI-Mind clinical study protocol

More than 10 million Europeans show signs of mild cognitive impairment (MCI), a transitional stage between normal brain aging and dementia stage memory disorder. The path MCI takes can be divergent; while some maintain stability or even revert to cognitive norms, alarmingly, up to half of the cases progress to dementia within 5 years. Current diagnostic practice lacks the necessary screening tools to identify those at risk of progression. The European patient experience often involves a long journey from the initial signs of MCI to the eventual diagnosis of dementia. The trajectory is far from ideal. Here, we introduce the AI-Mind project, a pioneering initiative with an innovative approach to early risk assessment through the implementation of advanced artificial intelligence (AI) on multimodal data. The cutting-edge AI-based tools developed in the project aim not only to accelerate the diagnostic process but also to deliver highly accurate predictions regarding an individual's risk of developing dementia when prevention and intervention may still be possible. AI-Mind is a European Research and Innovation Action (RIA H2020-SC1-BHC-06-2020, No. 964220) financed between 2021 and 2026. First, the AI-Mind Connector identifies dysfunctional brain networks based on high-density magneto- and electroencephalography (M/EEG) recordings. Second, the AI-Mind Predictor predicts dementia risk using data from the Connector, enriched with computerized cognitive tests, genetic and protein biomarkers, as well as sociodemographic and clinical variables. AI-Mind is integrated within a network of major European initiatives, including The Virtual Brain, The Virtual Epileptic Patient, and EBRAINS AISBL service for sensitive data, HealthDataCloud, where big patient data are generated for advancing digital and virtual twin technology development. AI-Mind's innovation lies not only in its early prediction of dementia risk, but it also enables a virtual laboratory scenario for hypothesis-driven personalized intervention research. This article introduces the background of the AI-Mind project and its clinical study protocol, setting the stage for future scientific contributions.

POS0377 ONE YEAR OF DIGITAL HEALTH APPLICATIONS (DiGA) IN GERMANY – RHEUMATOLOGISTS’ PERSPECTIVES

Background

Based on given legislation (§§ 33a and 139e SGB V, Social Code Book V) the German approach to digital health applications (Digitale Gesundheitsanwendungen, DiGA) allows reimbursed prescription of approved therapeutic software products (listed in the DIGA directory https://diga.bfarm.de/de/verzeichnis) for patients since October 6th, 2020.

Objectives

To evaluate the level of knowledge on DiGA among members of the German Society for Rheumatology (DGRh) after one year of DiGA under the conditions of the COVID-19 pandemic using the DiGA Toolbox of the ‘health innovation hub’ (hih), a think tank and sparrings partner of the German Federal Ministry of Health.

Methods

Anonymous cross-sectional online survey using LimeSurvey (https://limesurvey.org). The survey was promoted by newsletters sent out to DGRh newsletter recipients and Twitter posts. Ethical approval was obtained.

Results

75 valid participants reported that they care more than 80% of their working time for patients with rheumatic diseases. Most were working in outpatient clinics (54%) and older than 40 years of age (84%). Gender distribution was balanced (50%).

70% were aware of the possibility to prescribe DiGA. Most were informed on this for the first time via trade press (63%), and only 8% via the professional society. 46% expect information on DiGA from professional societies and the medical chambers (36%) but rarely from the manufacturer (10%) and the responsible ministry (4%). Respondents would like to be informed about DIGA via continuing education events (face-to-face 76%, online 84%), trade press (86%), and manufacturers test accounts (64%).

Only 7% have already prescribed a DiGA, 46% planned to do so, and 47% did not intend DiGA prescriptions. Relevant aspects for prescription are given in Figure 1.

Figure 1.

Aspects relevant for DiGA prescriptions; sorted by importance/number of mentions (participants needed to pick their three most relevant aspects from a pre-given list)

86% believe that using DiGA / medical apps would at least partially be feasible and understandable to their patients.

83% thought that data collected by the patients using DiGA or other digital solutions could at least partially influence health care positively.

51% appreciated to get DiGA data directly into their patient documentation system resp. clinical electronic health record (EHR) and 29% into patients’ owned EHR.

Conclusion

DiGA awareness was high whereas prescription rate was low. Mostly, physician-desired aspects for DiGA prescriptions were proven efficacy and efficiency for physicians and patients, risk of adverse effects and health care costs were less important. Evaluation of patients’ barriers and needs are warranted. Our results will contribute to the implementation and dissemination of DIGA.

Disclosure of Interests

Jutta G. Richter: None declared, Gamal Chehab: None declared, Philipp Stachwitz: None declared, Julia Hagen: None declared, Denitza Larsen: None declared, Johannes Knitza Consultant of: Vila Health, ABATON, Medac, Matthias Schneider: None declared, Anna Voormann: None declared, Christof Specker: None declared

The Small Acceptance Vertex Detector of NA61/SHINE

Charmonium production in heavy ion collisions is considered as an important diagnostic probe for studying the phase diagram of strongly interacting matter for potential phase transitions. The interpretation of existing data from the CERN SPS is hampered by a lack of knowledge on the properties of open charm particle production in the fireball. Moreover, open charm production in heavy ion collisions by itself is poorly understood. To overcome this obstacle, the NA61/SHINE was equipped with a Small Acceptance Vertex Detector (SAVD), which is predicted to make the experiment sensitive to open charm mesons produced in A-A collisions at the SPS top energy. This paper will introduce the concept and the hardware of the SAVD. Moreover, first running experience as obtained in a commissioning run with a 150 AGeV/c Pb+Pb collision system will be reported.

The Small Acceptance Vertex Detector of NA61/SHINE

Charmonium production in heavy ion collisions is considered as an important diagnostic probe for studying the phase diagram of strongly interacting matter for potential phase transitions. The interpretation of existing data from the CERN SPS is hampered by a lack of knowledge on the properties of open charm particle production in the fireball. Moreover, open charm production in heavy ion collisions by itself is poorly understood. To overcome this obstacle, the NA61/SHINE was equipped with a Small Acceptance Vertex Detector (SAVD), which is predicted to make the experiment sensitive to open charm mesons produced in A-A collisions at the SPS top energy. This paper will introduce the concept and the hardware of the SAVD. Moreover, first running experience as obtained in a commissioning run with a 150 AGeV/c Pb+Pb collision system will be reported.

Efficacy of afoxolaner plus milbemycin oxime chewable tablets (NexGard Spectra®, Merial) against adult Ancylostoma ceylanicum hookworm, in dogs

A fixed-combination chewable tablet incorporating afoxolaner plus milbemycin oxime (NexGard Spectra^®, Merial) was tested in purpose-bred Beagle dogs for efficacy against adult Ancylostoma ceylanicum hookworms. Sixteen dogs were inoculated each by oral administration of approximately 500 infective larvae of A. ceylanicum. Seventeen days after inoculation, the dogs were weighed and allocated randomly to be treated with afoxolaner plus milbemycin oxime chewable tablets or to remain untreated. Commercial chewable tablets of different strength were combined to deliver doses as close as possible to the minimum effective dose of 2.5mg afoxolaner plus 0.5mg milbemycin oxime per kg body weight. Parasites were recovered and counted for determination of efficacy seven days after treatment. All eight dogs that had been left untreated were harboring adult A. ceylanicum (geometric mean, 317.8; range, 210-428) while only one and nine A. ceylanicum were recovered from two of the eight dogs treated with afoxolaner plus milbemycin oxime chewable tablets (geometric mean, 0.5; p<0.0001). Thus, 99.9% efficacy against induced infection of A. ceylanicum was obtained by the use of oral NexGard Spectra^® at the minimum effective dose. Treatment with afoxolaner plus milbemycin oxime chewable tablets was well accepted and safe.

Alzheimer's Prevention Education: If We Build It, Will They Come? www.AlzU.org

BACKGROUND

Internet-based educational interventions may be useful for impacting knowledge and behavioral change. However, in AD prevention, little data exists about which educational tools work best in terms of learning and interest in participating in clinical trials.

OBJECTIVES

Primary: Assess effectiveness of interactive webinars vs. written blog-posts on AD prevention learning. Secondary: Evaluate the effect of AD prevention education on interest in participating in clinical trials; Assess usability of, and user perceptions about, an online AD education research platform; Classify target populations (demographics, learning needs, interests).

DESIGN

Observational.

SETTING

Online.

PARTICIPANTS

Men/Women, aged 25+, recruited via facebook.com.

INTERVENTION

Alzheimer's Universe (www.AlzU.org) education research platform.

MEASUREMENTS

Pre/post-test performance, self-reported Likert-scale ratings, completion rates.

RESULTS

Over two-weeks, 4268 visits were generated. 503 signed-up for a user account (11.8% join rate), 196 participated in the lessons (39.0%) and 100 completed all beta-testing steps (19.9%). Users randomized to webinar instruction about AD prevention and the stages of AD demonstrated significant increases (p=0.01) in pre vs. post-testing scores compared to blog-post intervention. Upon joining, 42% were interested in participating in a clinical trial in AD prevention. After completing all beta-test activities, interest increased to 86%. Users were primarily women and the largest category was children of AD patients. 66.3% joined to learn more about AD prevention, 65.3% to learn more about AD treatment.

CONCLUSIONS

Webinar-based education led to significant improvements in learning about AD prevention and the stages of AD. AlzU.org participation more than doubled interest in AD prevention clinical trial participation. Subjects were quickly and cost-effectively recruited, and highly satisfied with the AD education research platform. Based on these data, we will further refine AlzU.org prior to public launch and aim to study the effectiveness of 25 interactive webinar-based vs. blog-post style lessons on learning and patient outcomes, in a randomized, within-subjects design trial.

Implementing a systematic response to medication errors

Healthcare delivery is associated with various risks and it is unlikely that these can ever be completely eliminated. Medicine management is an area known to involve errors. This article describes how implementing a systematic response to medication errors enables health professionals to identify individual and organisational failures and reduce adverse patient outcomes.

Oral transmucosal fentanyl citrate versus placebo for painful dressing changes: a crossover trial

OBJECTIVE

Fentanyl is a potent opioid that is well absorbed via the oral mucosa. It can be given as an oral lozenge. The onset of analgesia is rapid and matches the pain profile observed at dressing changes.

METHOD

Patients experiencing pain during daily dressing changes were given entonox plus either placebo or oral transmucosal fentanyl citrate (OTFC) for two consecutive dressing changes in a randomised double-blind placebo-controlled crossover trial.

RESULTS

Nine patients were recruited. The mean worst pain score during dressing changes was 7/10 with placebo and 4/10 with OTFC; the reduction in pain achieved with OTFC was significant. The mean number of breaths of entonox taken during the dressing change was 27.67 with placebo and 4.67 with OTFC; the reduction in the number of entonox breaths with OTFC was significant. One patient in the OTFC group suffered nausea.

CONCLUSION

Compared with placebo, OTFC improved analgesia during painful dressing changes without an increase in side-effects.

Estimates of conserved microsynteny among the genomes of Glycine max, Medicago truncatula and Arabidopsis thaliana

A growing body of research indicates that microsynteny is common among dicot genomes. However, most studies focus on just one or a few genomic regions, so the extent of microsynteny across entire genomes remains poorly characterized. To estimate the level of microsynteny between Medicago truncatula (Mt) and Glycine max (soybean), and also among homoeologous segments of soybean, we used a hybridization strategy involving bacterial artificial chromosome (BAC) contigs. A Mt BAC library consisting of 30,720 clones was screened with a total of 187 soybean BAC subclones and restriction fragment length polymorphism (RFLP) probes. These probes came from 50 soybean contig groups, defined as one or more related BAC contigs anchored by the same low-copy probe. In addition, 92 whole soybean BAC clones were hybridized to filters of HindIII-digested Mt BAC DNA to identify additional cases of cross-hybridization after removal of those soybean BACs found to be repetitive in Mt. Microsynteny was inferred when at least two low-copy probes from a single soybean contig hybridized to the same Mt BAC or when a soybean BAC clone hybridized to three or more low-copy fragments from a single Mt BAC. Of the 50 soybean contig groups examined, 54% showed microsynteny to Mt. The degree of conservation among 37 groups of soybean contigs was also investigated. The results indicated substantial conservation among soybean contigs in the same group, with 86.5% of the groups showing at least some level of microsynteny. One contig group was examined in detail by a combination of physical mapping and comparative sequencing of homoeologous segments. A TBLASTX similarity search was performed between 1,085 soybean sequences on the 50 BAC contig groups and the entire Arabidopsis genome. Based on a criterion of sequence homologues <100 kb apart, each with an expected value of < or =1e-07, seven of the 50 soybean contig groups (14%) exhibited microsynteny with Arabidopsis.

Localization of astrovirus in experimentally infected turkeys as determined by in situ hybridization

Twenty-one 3-day-old turkey poults from British United Turkeys of America were orally inoculated with a recently characterized astrovirus, TAstV-2, isolated from turkeys with poult enteritis and mortality syndrome. At 1, 2, 3, 4, 5, 7, and 9 days postinfection (dpi), three inoculated birds were euthanatized, and tissues (intestines, spleen, bursa, and thymus) were collected immediately into 10% neutral buffered formalin. Inoculated birds were diarrheic by 3 dpi, and frothy feces persisted throughout the experimental period. Histologically, there was only slight evidence of enteric damage, which was characterized by mild epithelial necrosis, lamina propria infiltrates, minimal villus atrophy, and mild crypt hyperplasia. In situ hybridization, using a negative sense digoxigenin-labeled riboprobe to the capsid gene of TAstV-2, revealed viral RNA in intestinal epithelial cells at the basal margins of the villi, in distal small intestine, and in cecum at 2 dpi, with subsequent extension to epithelium of the large intestine and proximal small intestine (3-5 dpi). Minimal virus remained by 9 dpi.

Soybean genomic survey: BAC-end sequences near RFLP and SSR markers

We are building a framework physical infrastructure across the soybean genome by using SSR (simple sequence repeat) and RFLP (restriction fragment length polymorphism) markers to identify BACs (bacterial artificial chromosomes) from two soybean BAC libraries. The libraries were prepared from two genotypes, each digested with a different restriction enzyme. The BACs identified by each marker were grouped into contigs. We have obtained BAC- end sequence from BACs within each contig. The sequences were analyzed by the University of Minnesota Center for Computational Genomics and Bioinformatics using BLAST algorithms to search nucleotide and protein databases. The SSR-identified BACs had a higher percentage of significant BLAST hits than did the RFLP-identified BACs. This difference was due to a higher percentage of hits to repetitive-type sequences for the SSR-identified BACs that was offset in part, however, by a somewhat larger proportion of RFLP-identified significant hits with similarity to experimentally defined genes and soybean ESTs (expressed sequence tags). These genes represented a wide range of metabolic functions. In these analyses, only repetitive sequences from SSR-identified contigs appeared to be clustered. The BAC-end sequences also allowed us to identify microsynteny between soybean and the model plants Arabidopsis thaliana and Medicago truncatula. This map-based approach to genome sampling provides a means of assaying soybean genome structure and organization.

Soybean genomic survey: BAC-end sequences near RFLP and SSR markers

We are building a framework physical infrastructure across the soybean genome by using SSR (simple sequence repeat) and RFLP (restriction fragment length polymorphism) markers to identify BACs (bacterial artificial chromosomes) from two soybean BAC libraries. The libraries were prepared from two genotypes, each digested with a different restriction enzyme. The BACs identified by each marker were grouped into contigs. We have obtained BAC- end sequence from BACs within each contig. The sequences were analyzed by the University of Minnesota Center for Computational Genomics and Bioinformatics using BLAST algorithms to search nucleotide and protein databases. The SSR-identified BACs had a higher percentage of significant BLAST hits than did the RFLP-identified BACs. This difference was due to a higher percentage of hits to repetitive-type sequences for the SSR-identified BACs that was offset in part, however, by a somewhat larger proportion of RFLP-identified significant hits with similarity to experimentally defined genes and soybean ESTs (expressed sequence tags). These genes represented a wide range of metabolic functions. In these analyses, only repetitive sequences from SSR-identified contigs appeared to be clustered. The BAC-end sequences also allowed us to identify microsynteny between soybean and the model plants Arabidopsis thaliana and Medicago truncatula. This map-based approach to genome sampling provides a means of assaying soybean genome structure and organization.

Echocardiographic predictors of survival in low gradient aortic stenosis

Echocardiographic predictors of long-term survival for patients with low gradient aortic stenosis who undergo aortic valve replacement have not been previously reported. This study shows that patients with larger pre- and postoperative left ventricular volumes, a lower mean preoperative aortic pressure gradient, and failure of volumes to decrease and ejection fraction to increase postoperatively may have a poor prognosis.

MR artifacts, heat production, and ferromagnetism of Guglielmi detachable coils

The Guglielmi detachable coil, a platinum microcoil used in the endovascular treatment of intracranial aneurysms, was studied in vitro for its MR imaging artifacts, heat production, and ferromagnetism. In addition, imaging artifacts were studied in vivo in eight patients who had undergone therapeutic placement of these coils. These devices displayed a very low level of MR artifact and no ferromagnetism or heat production. We conclude that the Guglielmi detachable coil is compatible with MR imaging in terms of both safety and image quality.

Provision of clean injecting equipment

Providing clean needles and syringes to injecting drug users is one established strategy to prevent the spread of HIV and other blood borne infections ( 1 ). Our A&E department had been faced with problems from intravenous (IV) drug users requesting clean injecting equipment, and we wanted to know how other A&Es dealt with such requests, and whether they experienced similar problems.

Distinguishing detection from identification in subliminal auditory perception: a review and critique of Merikle's study

Assertions made by Merikle (1988) regarding audio subliminal messages were tested. Seventeen participants were presented subliminal messages embedded in a white-noise cover, and three signal-to-noise (S/N) detection ratios were examined. Participants were asked to guess message presence and message content, to determine subjective/objective thresholds. Results showed that participants were unable to identify target words presented in this audio subliminal stimulus format beyond chance levels.

Microcatheter embolization of non-neurologic traumatic vascular lesions

PURPOSE

The authors report their experience over a 28-month period with embolization of 23 non-neurologic traumatic vascular lesions in 21 patients with use of a coaxial microcatheter coil delivery system.

PATIENTS AND METHODS

The injuries included pseudoaneurysms (n = 17), arteriovenous fistulas (n = 3), and sites of extravasation (n = 3) and were caused by gunshot, shotgun, and stab wounds, as well as motor vehicle accidents and iatrogenic trauma. All microcatheter embolizations except one were performed with 2.2-F Tracker-18 catheters inserted coaxially through 5.0-5.5-F guiding catheters. In one case, a coaxial 3-F Teflon catheter was used. In all cases platinum microcoils (almost all non-fibril) and/or straight platinum embolization wires (with fibrils) were used.

RESULTS

Twenty-one (91%) of 23 vascular lesions were successfully occluded with use of the microcatheter system. The two cases in which microcatheter embolization failed were successfully managed by using larger catheters and steel coils. Two patients with hepatic vascular lesions (one site of extravasation and a pseudoaneurysm) and one patient with a lower extremity arteriovenous fistula required two procedures each for successful treatment. Procedures were life-saving in at least two patients. Two lesions recurred during follow-up ranging from 3 days to 17 months. Both of these recurrences were successfully treated with transcatheter embolization, in one case with use of microcatheters.

CONCLUSION

Microcatheter embolization with platinum coils and wires is an effective means for treating traumatic vascular lesions. A coaxial microcatheter system allows for easier, more rapid coil/wire delivery to smaller, spasm-prone arteries in such cases.

Implementation of practice guidelines in a clinical setting using a computerized knowledge base (Iliad)

We present the implementation of the indications for surgery for three surgical operations--cholecystectomy, cataract extraction, and knee arthroscopy--in a medical expert system, called Iliad. This implementation operates in the preauthorization service of IHC Health Plans (an insurance company in Salt Lake City) as a basis for reimbursement of services. Patient data collection forms, derived from Iliad knowledge base, were used by 13 participating surgeons to document the objective patient observations that justify the surgery and, then were faxed to IHC where a trained nurse input the data in Iliad. Iliad's decisions and reports on any deviations from guidelines are communicated back to the care provider. The study evaluates the impact of the computerized implementation on process, as measured by a questionnaire, and on outcome as measured by rate of approvals, documentation level, rate of requests, and average cost. The prospective implementation of the computerized guidelines has performed reliably, has been perceived as a preferred alternative to the old preauthorization system, and, most importantly, has enhanced significantly the level of documentation permitting evaluation and determination of appropriateness before surgery.

Generation and characterization of antipeptide antibodies to rat cytochrome P-450 side-chain cleavage enzyme

In this report, we describe the generation of immunologic probes to rat P-450scc. Two regions of the P-450scc amino acid sequence were identified (internal domain: amino acids 421-441; carboxy terminal domain: amino acids 509-526), chemically synthesized and used as immunogens in rabbits. Antibody production was monitored by enzyme-linked immunoassay (EIA) and Western blot analyses. Antisera were successfully generated to each of the P-450scc regions that recognized the entire 49 kDa rat P-450scc protein. Antiserum directed to the internal domain of P-450scc showed broad species crossreactivity, whereas antiserum directed to the carboxy terminal domain of P-450scc crossreacted with only rat and mouse. Both antisera were useful for Western blot and immunocytochemical analyses of rat P-450scc expression. In addition to recognizing the major 49 kDa P-450scc protein, each antiserum also recognized lower molecular weight species. Antiserum directed to the internal domain of P-450scc specifically recognized a 42 kDa species, whereas antiserum directed to the carboxy terminal domain specifically recognized an 8 kDa species. We hypothesize that the two lower molecular weight immunoreactive species are generated by proteolytic cleavage of rat P-450scc between the internal and carboxy terminal epitopes.

Identification and immunochemical characterization of a major placental secretory protein related to the prolactin-growth hormone family, prolactin-like protein-C

Trophoblast cells of the rat chorioallantoic placenta synthesize and secrete a number of proteins structurally related to pituitary PRL. During the purification of one member of the placental PRL family, PRL-like protein-A (PLP-A), we identified a major contaminating protein with a similar mol wt but possessing a more acidic pI (5.9-6.1) and different immunoreactivities. After isolation by two-dimensional gel electrophoresis, the more acidic contaminating protein was electroeluted, and its N-terminal amino acid sequence was determined by gas phase sequencing. The N-terminal sequence showed considerable homology with members of the PRL family, including characteristic positioning of cysteine residues at amino acids 4 and 11. The newly identified protein species have been termed PLP-C based on their structural similarity with pituitary PRL. The protein was further characterized by the generation of specific immunological probes. Antibodies were generated to electrophoretically purified protein and to a chemically synthesized peptide representing amino acids 11-32 of its N-terminal sequence. Each antiserum specifically recognized two major species migrating at approximately 25 and 29 kDa, respectively. The 29-kDa species specifically bound to Concanavalin-A, while the 25-kDa species failed to bind to the lectin. Furthermore, the 29-kDa species could be converted to the 25-kDa species by enzymatic deglycosylation. The antisera have also been used to examine the cell- and temporal-specific patterns of expression. The immunoreactive protein species (25 and 29 kDa) were localized primarily to spongiotrophoblast cells present in the junctional zone of the chorioallantoic placenta. Expression was initiated after midgestation and increased during the remaining part of gestation. In summary, PLP-C is a major secretory protein produced by spongiotrophoblast cells during the second half of gestation.

Expression of alkaline phosphatase in differentiated rat labyrinthine trophoblast tissue

In this report, we describe the generation of specific antibodies to rat alkaline phosphatase and the temporal and regional characteristics of alkaline phosphatase expression during maturation of the rat chorioallantoic placenta. An antipeptide antiserum was generated to the amino terminal 15 amino acids of rat alkaline phosphatase. The antiserum specifically recognized alkaline phosphatase. Alkaline phosphatase expression was monitored in the junctional and labyrinth zones of the chorioallantoic placenta by Western and Northern blot analyses. Alkaline phosphatase protein and mRNA were present in both the junctional and labyrinth zones on day 13 of gestation. As gestation advanced, alkaline phosphatase mRNA and protein expression decreased below the limits of detection in the junctional zone, while alkaline phosphatase expression increased in the labyrinth zone. Labyrinthine alkaline phosphatase migrated predominantly as a 95-kDa species, whereas rat kidney expressed exclusively the 75-kDa species. Enzymatic deglycosylation of the 75- and 95-kDa alkaline phosphatase species resulted in the generation of a 55-kDa species. In summary, alkaline phosphatase expression is a useful indicator of trophoblast differentiation.

Color Doppler sonography of the scrotum

Color Doppler sonography is a noninvasive, rapidly performed, and relatively inexpensive imaging technique for use in the diagnosis of scrotal pathology. Its major and proven role is in the evaluation of patients with acute scrotal pain, for which it is likely to become the primary imaging modality. Further work is needed to determine whether color Doppler is a useful diagnostic adjunct in evaluating patients with varicoceles and scrotal masses.

Identification and characterization of a new member of the prolactin family, placental lactogen-I variant

This report describes the identification and characterization of a new member of the placental prolactin (PRL) family, termed placental lactogen-I variant (PL-Iv). PL-Iv was isolated from medium conditioned by late gestation placental explants. Rat PL-Iv was found to be closely related to rat PL-I. Amino-terminal sequence analysis indicated that PL-Iv shared approximately 88% sequence identity with the amino terminus of PL-I. PL-Iv proteins cross-reacted with antiserum to recombinant mouse PL-I and PL-Iv mRNA hybridized with a PL-I cDNA. Multiple PL-I and PL-Iv species were present in placental cytosol. Despite the structural similarities between PL-I and PL-Iv, distinct differences were also evident. Antibodies generated to the amino-terminal 19 amino acids of PL-Iv specifically recognized PL-Iv, while failing to recognize PL-I. Secreted PL-Iv had an affinity for concanavalin A, whereas secreted PL-I lacked affinity for the lectin. PL-I was predominantly secreted as a 36-40-kDa species and PL-Iv was predominantly secreted as a 33-kDa species. Furthermore, PL-I and PL-Iv were synthesized at different times during gestation and by different cell types. PL-I was synthesized by trophoblast giant cells during the first half of gestation, while PL-Iv was predominantly synthesized by spongiotrophoblast cells during the later stages of gestation. PL-Iv was shown to stimulate the proliferation of rat Nb2 lymphoma cells, an in vitro measure of lactogenic activity. In summary, PL-Iv shares structural similarities with PL-I; however, it shows other structural differences in addition to unique cell- and temporal-specific patterns of expression in the rat chorioallantoic placenta.

Potential Ambergris Odorants From Abietic Acid

In contrast to literature reports the rearrangement of abietic acid (1) catalysed by 96% sulfuric acid gives a mixture (3 : 1) of two dienoic acids (19) and (27) whose structures have been established by spectral means. Compounds containing the diene system are unstable, severely limiting their use in synthesis. However, removal of the diene functionality affords stable compounds which, despite difficulties in stereochemical control, are suitable for further modification. The synthesis of compounds containing a five- membered C-ring common to a class of potential amber odorants is reported.

Specific antibody responses and generation of antigenic variants in chickens immunized against a virulent avian influenza virus

To examine the specificity of the antibody response to the influenza hemagglutinin and the generation of antigenic variants, chickens were immunized against the highly virulent H5 virus A/Ty/Ont/7732/66 (H5N9) and then challenged with a lethal dose of the virus. The antibody responses of these chickens to the hemagglutinin (HA) were examined with an enzyme-linked immunosorbent assay (ELISA) in which their sera were titrated for the ability to block the binding of monoclonal antibodies (MAbs) to five distinct neutralizing epitopes on the viral HA. Based on the ELISA results, a majority (5/6) of the chickens produced antibodies to three of the five neutralizing epitopes on the viral HA. After challenge, two of six immunized chickens shed virus and died; antigenic comparisons of isolates from these two chickens indicated the presence of an antigenic variant; i.e., there was a change in one neutralizing epitope on the HA of virus shed by one chicken. None of the chickens had produced antibodies to this particular epitope on the viral HA. Inoculation of chickens with this variant resulted in 100% mortality, demonstrating that a change in this particular epitope did not alter the virulence of the virus. These studies indicate that chickens immunized against highly virulent influenza viruses may excrete virulent variants following challenge with live virus.

Persistence of antibody and response to booster dose of Haemophilus influenzae type b polysaccharide diphtheria toxoid conjugate vaccine in infants immunized at 9 to 15 months of age

At approximately 2 years of age, 27 infants previously immunized at 9 to 15 months of age with two doses of polyribosylribitol phosphate-diphtheria toxoid conjugate vaccine (PRP-D) and 23 infants immunized with polyribosylribitol phosphate (PRP) vaccine were given a single injection of PRP-D. Pre- and post-immunization sera were obtained. No serious local or systemic reactions were observed. The PRP-D recipients had a geometric mean anti-PRP antibody level of 4.8 micrograms/ml 1 month after the second primary injection, retained 1.2 microgram/ml 1 year later, and had a level of 71 micrograms/ml after the booster immunization. In contrast, PRP recipients had a geometric mean level of 0.083 microgram/ml 1 month after the second primary injection, retained 0.042 microgram/ml 1 year later, and after a single dose of PRP-D at approximately 2 years of age had a geometric mean level of 8.6 micrograms/ml. The significantly higher antibody response in the prior PRP-D recipients suggests the recall of immunologic memory induced by the PRP-D vaccine.

The walk-in anergic patient. How best to assess the risk of sepsis following elective surgery

This prospective study evaluated host resistance in a surgical population who walked into the hospital for elective surgery. Patients were stratified into Hospital Reactive (HR, n = 19) if they reacted to two or more of five recall skin test antigens and Walk-in Anergic (WA, n = 26) if they did not react to the antigens. The WA patients were slightly older (74.4 +/- 1.8 years, +/- SEM versus 66.7 +/- 2.7 p less than 0.05). Diagnosis in the HR and WA group were: tumors 13/19 versus 21/26, diverticulitis 3/19 versus 0/19, and miscellaneous 3/19 versus 5/26. Twenty-five laboratory normal controls (LN) were also studied. There were no significant differences in the following parameters between the HR and WA groups: stage of disease; hemoglobin; circulating leukocyte count; polymorphonuclear cell counts; total lymphocyte counts (both groups lower than LN, p less than 0.05), monocyte counts (both higher than LN, p less than 0.05); per cent E-rosettes and lymphocyte blastogenesis to mitogens (phytohemagglutinin, concanavalin-A) and antigens (purified protein derivative and tetanus); phagocytosis of preopsonised Staphylococcus aureus 502A, at 5, 10, and 20 minutes; alpha, beta, and gamma globulins; C3, and total hemolytic complement (CH50) levels; C-reactive protein; and ANA and DNA levels. The HR group demonstrated an increase in the rate of killing of Staphylococcus 502A at 10, 20, 40, and 80 minutes compared to the LN group but the WA group did not show this augmentation (p less than 0.001). The serum albumins were: LN = 4.46, HR = 3.98, WA = 3.43 g/dl (p less than 0.05). Degree and duration of surgery was the same in the HR and WA groups. There were no major sepsis episodes (bacteremia or proven intracavitary abscess) in the HR patients versus 25% in the WA patients (p less than 0.05). There was one death (6%, pulmonary embolus) in the HR group and 8 (40%) in the WA group (p less than 0.05). Antibiotic prophylaxis was equal but the WA patients received therapeutic antibiotics more frequently (65% versus 11% p less than 0.05). Of all the host immunocompetence tests measured in this study, the delayed type hypersensitivity skin test response and the serum albumin were variables abnormal between the survivors and those who died.

Diazomethyl ketone substrate derivatives as active-site-directed inhibitors of thiol proteases. Papain

The diazomethyl ketones of z-Phe-Phe inactivate papain by a stoichiometric reaction at the active-center thiol. Since the reagents are stable in mercaptoethanol, their reaction with papain is judged to be the result of complex formation characteristic of affinity-labeling reagents. The diazomethyl ketones react by a mechanism different from that of chloromethyl ketones, since the pH dependence of their inactivation of papain is different, the rate increasing with decreasing pH. This relationship has been observed in other cases, such as in the reaction of azaserine with glutamine amidotransferases [Buchanan, J. M. (1973), Adv. Enzmol. Relat. Areas Mol. Biol. 39, 91], and is interpreted as an indication of reaction with a thiol group in its protonated form.

Active-site-directed alkylation of chymotrypsin by reagents utilizing various departing groups

Affinity-labeling reagents are useful for the inactivation of proteases in vivo but are apparently limited in application by the possibility of side reactions. In addition, increased specificity would be desirable. Substrate-derived chloromethyl ketones, one class of protease inhibitors, have been examined with the hope that replacement of the departing group halogen by other substituents might lead to improved inhibitor characteristics. Analogues of Z-Phe-Ch2X were synthesized in which X is a sulfonate or carboxylate substituent and examined as inactivators of chymotrypsin. The sulfonate esters were found to be more reactive than the previously studied halogen derivatives.