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Development of bone-like substance in cartilaginous rat nasal septum under experimental conditions.

The anterior part of the mammalian nasal septum (NS) persists throughout the life span as hyaline cartilage, in contrast to cartilage in most parts of the body, which is gradually replaced by bone during development. In this study, we have cultured differentiating rat NS under various experimental conditions in an attempt to gain some insight into the osteogenic potential, if any, of the NS and its surrounding connective tissue. Differentiating NS from E15 and E19 rat embryos were dissected and grown under the following conditions: 1) organ cultured in Waymouth's medium or modified Eagle's medium, with or without serum; 2) cultured on chick chorioallantoic membrane (CAM); 3) implanted under rat kidney capsule (KC). Bone-like substance (BLS) never developed in organ cultures, but was observed in CAM cultures and KC implants after 7 days. The BLS was located external to the perichondrium of the NS and was stained red by the van Gieson's technique, indicating the presence of mature collagen. Further evidence of its bone-like characteristics was demonstrated by the presence of alkaline phosphatase and type I collagen. The CAM and KC represent two experimental conditions under which progenitor cells in the nasal septum area may be induced to synthesize BLS.

Allantois↗

The growth of nerves in relation to the formation of premuscle cell masses in the developing chick forelimb.

A description is given of the growth of segmental nerves 13 to 16 (SN13 to SN16) from the brachial myotomes into the ventral and dorsal premuscle cell masses of the chick forelimb. At stage 25 (Hamburger and Hamilton, '51), segmental nerves have converged to form two nerve trunks which enter the ventral and dorsal premuscle cell masses. These nerves grow into the limb, parallel to its proximodistal axis. The nerve trunk in the ventral compartment, the brachialis longus inferior (bli n), grows on the brachial artery as far as the metacarpals. The nerve trunk in the dorsal compartment, the brachialis longus superior (bls n), grows on the precartilage adjacent to a dorsal premuscle density as far as the metacarpals. The brachialis longus inferior and superior nerve trunks give rise to a number of nerves during their growth to the metacarpals. Each of these nerves appears at the time of formation of a new premuscle cell density. At late stage 25, a posterior and ventral premuscle density forms in the middle of the stylopodium; posterior fascicles of the bli n diverge at this level and grow toward this new density to form the ulnar nerve. By stage 26 a posterior and ventral premuscle density is prominent over the bli n, at the junction of the stylopodium and the zeugopodium; ventral fascicles of the bli n grow into this density to form the flexor digitorum profundus nerve. At this stage a posterior and dorsal premuscle density forms just beyond the junction of the stylopodium and zeugopodium. Posterior fascicles of the bls n diverge at this level and grow toward this density to form a nerve from which the extensor metacarpi ulnaris, extensor digitorum communis, and radialis laterialis nerves are destined to form. At stage 29 the premuscle cell masses of the autopodium have formed. The remaining nerve fascicles comprising the bls n (the radialis profundus nerve) grow into the autopodium and branch to innervate each of the dorsal premuscles. The remaining nerve fascicles comprising the bli n (the middle nerve) grow into the autopodium and branch to innervate each of the ventral premuscles.

Animals↗

Interphase fluorescence in situ hybridization for detection of 8q24/MYC breakpoints on routine histologic sections: validation in Burkitt lymphomas from three geographic regions.

A chromosomal translocation involving the MYC gene is characteristic of Burkitt lymphoma (BL) and represents a molecular disease marker with diagnostic and clinical implications. The detection of MYC breakpoints is hampered by technical problems, including the distribution of the breakpoints over a very large genomic region of approximately 1,000 kb. In this article, we report on the testing and validation of a segregation fluorescence in situ hybridization (FISH) assay for MYC breakpoints on a large series of BLs. A contig of overlapping genomic clones was generated, and two probe sets flanking the MYC gene were selected. Both probe sets were tested in an interphase FISH segregation assay on 8 B-cell lymphoma cell lines and 32 lymphoma samples with proved 8q24/MYC abnormalities and validated in 47 BLs from The Netherlands, Brazil, and Uganda. MYC translocation breakpoints were identified in 98% of the tumors of the test series and in 89% of the cases of the validation series. In 89% of all positive samples, the breakpoints were located between 190 kb 5' and 50 kb 3' of MYC. Nine cases had more distant breakpoints, and in one patient an insertion of MYC into the IGH region was detected. In two of the three BLs lacking CD10 expression, no breakpoint could be detected, suggesting that CD10 is a discriminative marker of BL. We did not find consistent differences between BL and atypical BL in incidence of an MYC breakpoint.

Adolescent↗

Promiscuous expression of Epstein-Barr virus genes in Burkitt's lymphoma from the central African country Malawi.

Primary BL in Malawian children has a very high frequency association, approaching 100%, with the human herpesvirus EBV. A detailed study carried out on viral gene expression in these tumours, using both fresh material and methanol-fixed FNAs, showed, contrary to prediction, that most belong to a variant "class II" latency category, with lytic cycle-related genes also expressed. That is, in addition to EBNA1 expression, membrane proteins (LMP1/2A), immediate early (BZLF1) and early (IR2 and IR4) genes, a putative viral oncogene (BARF1), CST (BART) antisense transcripts and the viral bcl-2 homologue are expressed in a high proportion of the BLs. Most, but not all, express the small viral (EBER) RNAs. Two other significant observations were made: (i) in addition to expression of cellular cytokine (IL-10) transcripts in all tumours investigated, the normally silent viral IL-10 homologue was expressed in some tumours; (ii) whereas EBNA1 expression from its restricted Qp promoter was generally observed, the nonrestricted Cp/Wp promoter was also active in some tumours. Viral gene expression in the Malawian [endemic (e)] BLs appears to be more promiscuous than predicted from other studies, but expression accords with the cytopathologic picture of eBLs as a rapidly proliferating cell population accompanied by considerable necrosis, and a clinically diverse disease. A small-scale study of relapse Malawian BLs revealed a different picture of viral association, more akin to systemic BL than eBL, where EBV appears to be absent or present only at very low levels. The significance of these findings is considered.

Antigens, Viral↗

Correlation between the growth-inhibitory effect of TGF-beta 1 and phenotypic characteristics in a panel of B-cell lines.

Human B-cell lines established from Burkitt lymphoma (BL) and normal B cells immortalized in vitro by EBV (LCLs) differ in phenotype. While the BL correspond to resting B cells, the LCLs resemble activated B cells. When BLs which have the EBV genome are carried in vitro, they acquire some of the features of LCLs, such as expression of B-cell activation markers and the tendency to form aggregates. Comparison of several B-cell lines for sensitivity to TGF-beta showed that the growth of BLs (with few exceptions), but not of the LCLs, was inhibited. The results suggested that the sensitivity to TGF-beta correlates with the cellular phenotype. In the present work, this assumption is even more critically substantiated by studying 2 sublines of an EBV-genome carrying BL line, Mutu, which were selected for single cells and aggregates. The former (with resting phenotype) was inhibited, while the subline of aggregated cells, which also expressed B-cell activation markers, was not inhibited. Somatic-cell hybrids between BLs, LCLs and non-B cells provided lines with phenotypic differences. Results with a panel of such hybrid lines also showed that those which express the activated B-cell phenotype are not inhibited by TGF-beta. Differences in the levels of expression of activation markers did not influence the response to TGF-beta.

B-Lymphocytes↗

Altered flexibility in the substrate-binding site of related native and engineered high-alkaline Bacillus subtilisins.

High-alkaline serine proteases have been successfully applied as protein degrading components of detergent formulations and are subject to extensive protein engineering efforts to improve their stability and performance. Dynamics has been suggested to play an important role in determining enzyme activity and specificity and it is therefore of interest to establish how local changes in internal mobility affect protein stability, specificity and performance. Here we present the dynamic properties of the 269 residue serine proteases subtilisin PB92 (Maxacal(TM)) and subtilisin BLS (Savinase(TM)), secreted by Bacillus lentus, and an engineered quadruple variant, DSAI, that has improved washing performance. T1, T2 and heteronuclear NOE measurements of the 15N nuclei indicate that for all three proteins the majority of the backbone is very rigid, with only a limited number of residues being involved in local mobility. Many of the residues that constitute the S1 and S4 pockets, determining substrate specificity, are flexible in solution. In contrast, the backbone amides of the residues that constitute the catalytic triad do not exhibit any motion. Subtilisins PB92, BLS and DSAI demonstrate similar but not identical NMR relaxation rates. A detailed analysis of local flexibility indicates that the motion of residues Thr143 and Ala194 becomes more restricted in subtilisin BLS and DSAI. Noteworthy, the loop regions involved in substrate binding become more structured in the engineered variant as compared with the two native proteases, suggesting a relation between altered dynamics and performance. Similar conclusions have been established by X-ray crystallograpic methods, as shown in the accompanying paper.

Bacillus↗

["Topless" cardiopulmonary resuscitation. Fashion or science?].

A decade after the onset of a discussion whether ventilation could be omitted from bystander basic life support (BLS) algorithms, the state of the evidence is reevaluated. Initial animal studies and a prospective randomized patient trial had suggested that omission of ventilation during the first minutes of lay cardiopulmonary resuscitation (CPR) did not impair patient outcomes. More recent studies demonstrate, however, that this may hold true only in very specific scenarios, and that the chest compression-only technique was never superior to standard BLS. Instead of calling basics of BLS training and practice into question, more and better training of lay persons and professionals appears mandatory, and targeted use of dispatcher-guided telephone CPR should be evaluated and, if it improves outcome, it should be encouraged. Future studies should focus much less on the omission but on the optimization of ventilation under the specific conditions of CPR.

Cardiopulmonary Resuscitation↗

Two novel mutations in the MHC class II transactivator CIITA in a second patient from MHC class II deficiency complementation group A.

Congenital MHC class II deficiency or bare lymphocyte syndrome (BLS; McKusick 209920) is caused by defects in trans-acting regulatory factors that control MHC class II expression and is therefore a disease of gene regulation. There are at least four complementation groups and the genetic and molecular dissection of this rare disease has contributed considerably to our current understanding of the molecular mechanisms governing MHC class II expression. Identification of the gene that is defective in BLS complementation group A, CIITA (MHC class II transactivator), has led to the discovery that CIITA acts as a master control factor of MHC class II expression. We have identified the CIITA mutations in a second patient from BLS group A. Two novel mutations abolish CIITA function, as shown by transfection experiments. Molecular analysis of these two novel mutations, together with the one described earlier in the first patient, is informative in terms of CIITA structure-function relationships.

Alleles↗

The blind loop syndrome in children.

Anatomical abnormalities of the small bowel that cause intestinal stagnation result in bacterial overgrowth and a blind loop syndrome (BLS). Bacterial breakdown of bile salts and deamination of protein lead to malabsorption, steatorrhea, and fat-soluble vitamin deficiencies. Four children developed BLS as a complication of necrotizing enterocolitis, jejunal atresia, gastroschisis, and biliary atresia. BLS was suggested by abdominal pain, feculent vomiting, steatorrhea, and hypoalbuminemia. Dilated, stagnant bowel loops were demonstrated in each instance by upper gastrointestinal contrast study. Positive intestinal bacterial aspirates were confirmatory. Antibiotic treatment in two patients improved symptomatology but all children ultimately required surgery. Surgical procedures consisted of blind loop resection, intestinal plication, and catheterization of the bilioenteric conduit. All patients are now asymptomatic but one child suffers from parenteral nutrition-related cirrhosis and another requires chronic antibiotic therapy.

Bacterial Infections↗

Organizing and implementing a hospital-wide first-responder automated external defibrillation program: strengthening the in-hospital chain of survival.

First-responder automated external defibrillation (AED) in the hospital is consistent with the American Heart Association's (AHA) early defibrillation standard or care. With trained personnel and automated external defibrillators immediately available, early defibrillation should have a greater impact on survival than early cardiopulmonary resuscitation (CPR). Therefore, in our hospitals we modified basic life support to include automated external defibrillation (BLS-AED) for all personnel who are expected to respond to a cardiac arrest, with rapid defibrillation taking priority over CPR. We describe how we organized and implemented this hospital-wide first-responder BLS-AED program. Planning the process includes gaining support from key leaders who are responsible for resuscitation practice, and identifying the target audience of the training program. Hospital unit needs for AED or conventional defibrillation and equipment must be identified, the training program developed, and existing policies and procedures modified. Several barriers to implementation may exist. Education about the efficacy and safety of AED and experience once the BLS-AED program is in place can overcome attitudes and bias. Concerns about the cost of equipment and training must be addressed. Program evaluation may include patient issues such as measuring the time to the first defibrillation and patient outcome; as well as training and retention issues.

Adult↗

Cardiopulmonary resuscitation training for UK undergraduate dental students.

Cardiopulmonary resuscitation (CPR) is a vital skill which must be mastered by all health care professionals. The General Dental Council recommends that it is taught to all UK dental undergraduates. This study was done to elicit how many schools teach aspects of Basic and Advanced Life Support to their students, how often and whether they assess their students. All UK schools teach Basic Life Support (BLS) at least once, but a lower proportion assess their students formally and only three schools teach BLS in each year of the course. Only 64% (9/14) of respondents thought their students received enough training to be able to cope with the initial stages of an emergency on their own. Thus, although the level of BLS training is probably acceptable at present, further improvement of CPR training in UK Dental Schools is advisable.

Cardiopulmonary Resuscitation↗

Molecular weights and molecular-weight distributions from ultracentrifugation of nonideal solutions.

Ultracentrifugation, membrane osmometry and capillary viscometry experiments have been performed on two dextran samples, which have molecular-weight distributions (MWDs) similar to those of dextrans used as blood plasma extenders. The manufacturer reported values of Mn and MW, determined by end group analysis and by light scattering, respectively. Our values of Mn, determined by osmometry, and MW, calculated from ultracentrifugal and viscometry experiments, agreed quite well with the manufacturer's results. Good agreement was obtained with values of MW and BLS (the light scattering second virial coefficient) obtained from sedimentation equilibrium experiments at different speeds using sector or nonsector-shaped centerpieces. Several ways of obtaining MW, MZ and BLS from sedimentation equilibrium experiments are presented. We have also shown how to obtain the speed-dependent term of the sedimentation equilibrium second virial coefficient. Both BLS and the speed-dependent nonideal terms could be used to correct the sedimentation equilibrium data, so that ideal values of d in c/d(r2) or dc/d(r2) could be estimated and used to obtain the MWDs of the dextran samples. Both Donnelly's and Scholte's methods were used with the sedimentation equilibrium data. With both methods, unimodal MWDs were encountered, which gave good agreement with the manufacturer's MWDs, obtained by a combination of analytical gel chromatography and light scattering. Uncorrected sedimentation equilibrium data gave MWDs quite different from the manufacturer's results. The MWD calculated from the differential distribution of sedimentation coefficients also gave a unimodal MWD, but this MWD did not give a good agreement with the sedimentation equilibrium results or with the manufacturer's results.

Dextrans↗

Plasma norepinephrine concentrations during resuscitation in the dog.

The objective of this study was to evaluate whether the adrenal glands contribute to the increase in plasma norepinephrine concentrations during cardiopulmonary resuscitation, by releasing norepinephrine and/or by secreting epinephrine that facilitates the release of norepinephrine from sympathetic nerve endings via stimulation of presynaptic beta receptors. The experiments were performed in adrenalectomized and in sham-operated dogs. In adrenalectomized dogs the increase in plasma norepinephrine concentrations during cardiopulmonary arrest and basic life support (BLS) was markedly smaller than in sham-operated dogs. Intravenous infusion of physiologic doses of epinephrine during BLS in adrenalectomized animals did not influence the plasma norepinephrine concentrations. These data indicate that, as suggested by others, the marked increase in plasma norepinephrine concentrations during BLS in dogs is mainly of adrenomedullary origin. They also suggest that presynaptic facilitation of norepinephrine release by epinephrine is not important, but further experiments using higher doses of epinephrine are necessary.

Adrenal Glands↗

Effectiveness of mouth-to-mouth resuscitation performed by young adolescents on a mannequin.

Bystanders are reluctant to perform basic life support (BLS) because of fear of failure and of infection, especially with mouth-to-mouth resuscitation (MTM). A possibility to enhance willingness could be the giving of MTM or BLS instructions at a very early age to the potential rescuers. The study aimed to investigate the effectiveness of MTM with respect to ventilation and the time needed for performing 5 ventilations. In this study, MTM was performed on a mannequin by 57 children and adolescents aged 10 and 14 years. This study showed that 14-year-olds effectively perform MTM, reaching the recommended tidal volumes. Ten-year-old children have already developed sufficient motor skills for MTM with no significant time differences compared with the 14-year-olds. However, physical demands may be rather high at this age. Further long-term studies are needed to investigate clinical benefits of early teaching of MTM or BLS that may lead to international guidelines with low age limits.

Adolescent↗

Studies on diaminoglyoxime (DAG): thermolysis and evaluation as ballistic modifier in double base propellant.

This paper reports thermolysis of diaminoglyoxime (DAG) and its evaluation as a ballistic modifier in double base propellant formulations. Differential scanning calorimetry (DSC) and simultaneous thermal analysis (DTA-thermogravimetric (TG)) revealed that DAG decomposes in two stages. Kinetics of initial stage of thermal decomposition of DAG evaluated from TG data gave activation energy (E(a)) of 153 kJmol(-1). The high-temperature Fourier transform Infrared (FTIR) spectra of DAG suggested preferential cleavage of NO and CNH2 during decomposition. Mass spectral data also suggest possibility of similar process. The hyphenated TG-FTIR data also revealed the evolution of gases containing species, such as CN, NH, OH and oxides of nitrogen during thermal decomposition. Evaluation of DAG as a ballistic modifier in RDX incorporated double base propellant formulations indicated that it brings down the pressure index to 0.17 compared to 0.79 for a control composition in the pressure range 6.9-8.8 MPa when used in combination with basic lead salycilate (BLS). The study suggests that combination of DAG and BLS need to be optimized to achieve more remarkable effects than BLS alone. It was observed that DAG does not have adverse effect on vulnerability and chemical stability of the propellant formulation.

Aerosol Propellants↗

Survival from prehospital cardiac arrest is critically dependent upon response time.

STUDY OBJECTIVE: This study correlated the delay in initiation of bystander cardiopulmonary resuscitation (ByCPR), basic (BLS) or advanced cardiac (ACLS) life support, and transport time (TT) to survival from prehospital cardiac arrest. This was a secondary endpoint in a study primarily evaluating the effect of bicarbonate on survival. DESIGN: Prospective multicenter trial. SETTING: Patients treated by urban, suburban, and rural emergency medical services (EMS) services. PATIENTS: Eight hundred and seventy-four prehospital cardiac arrest patients. INTERVENTIONS: This group underwent conventional ACLS intervention followed by empiric early administration of sodium bicarbonate noting resuscitation times. Survival was measured as the presence of vital signs on emergency department (ED) arrival. Data analysis utilized Student's t-test and logistic regression (p<0.05). RESULTS: Survival was improved with decreased time to BLS (5.52 min versus 6.81 min, p=0.047) and ACLS (7.29 min versus 9.49 min, p=0.002) intervention, as well as difference in time to return of spontaneous circulation (ROSC). The upper limit time interval after which no patient survived was 30 min for ACLS time, and 90 min for transport time. There was no overall difference in survival except at longer arrest times when considering the primary study intervention bicarbonate administration. CONCLUSION: Delay to the initiation of BLS and ACLS intervention influenced outcome from prehospital cardiac arrest negatively. There were no survivors after prolonged delay in initiation of ACLS of 30 min or greater or total resuscitation and transport time of 90 min. This result was not influenced by giving bicarbonate, the primary study intervention, except at longer arrest times.

Adolescent↗

Brucella spp. lumazine synthase: a novel antigen delivery system.

Lumazine synthase from Brucella spp. (BLS) was evaluated as a protein carrier to improve antigen delivery of KETc1, one of the peptides of the anti-cysticercosis vaccine. KETc1 becomes antigenic, preserved its immunogenicity and its protective capacity when expressed as a recombinant chimeric protein using Brucella spp. lumazine synthase. KETc1 and BLS-KETc1 were not MHC H-2(d), H-2(k) nor H-2(b) haplotype-restricted albeit KETc1 is preferentially presented in the H-2(b) haplotype. These findings support that BLS is a potent new delivery system for the improvement of subunit vaccines.

Animals↗

Prehospital care and survival of pediatric patients with blunt trauma.

BACKGROUND: The aim of this study was to compare the outcome of severe blunt trauma in children receiving prehospital care from either physician-staffed advanced life support (ALS) units, or from basic life support (BLS) units staffed by emergency medical technicians. METHODS: The records of 288 children with severe blunt trauma who required intensive care in the regional level 1 trauma center or who died from their injuries were analyzed retrospectively. Patients were excluded if resuscitation at the scene was not attempted, if the level of prehospital care was unspecified, or if arrival at the level 1 trauma center was delayed beyond 150 minutes. Seventy-two patients met the inclusion criteria of BLS-, and 49 the criteria of ALS-prehospital care. RESULTS: A reduced mortality rate (22.4% v 31.9%) was seen in the ALS group, which was more apparent in a "salvageable but high-risk" subgroup, characterized by Glasgow Coma of Scale 4 through 8, Pediatric Trauma Score of 0 through 5, and Injury Severity Score (ISS) of 25 through 49. However, a statistically significant difference was only seen when trauma severity was evaluated by the ISS. CONCLUSION: An improved outcome in children with severe blunt trauma has been demonstrated when prehospital care is provided by physician-staffed ALS units compared with BLS units.

Adolescent↗