Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Awareness during General Anaesthesia in the First 4,000 Incidents Reported to webairs

The aim of this study was to analyse the incidents related to awareness during general anaesthesia in the first 4,000 cases reported to webAIRS—an anaesthetic incident reporting system established in Australia and New Zealand in 2009. Included incidents were those in which the reporter selected “neurological” as the main category and “awareness/dreaming/ nightmares” as a subcategory, those where the narrative report included the word “awareness” and those identified by the authors as possibly relevant to awareness. Sixty-one awareness-related incidents were analysed: 16 were classified as “awareness”, 31 were classified as “no awareness but increased risk of awareness” and 14 were classified as “no awareness and no increased risk of awareness”. Among 47 incidents in the former two categories, 42 (89%) were associated with low anaesthetic delivery and 24 (51%) were associated with signs of intraoperative wakefulness. Memory of intraoperative events caused significant ongoing distress for five of the 16 awareness patients. Patients continue to be put at risk of awareness by a range of well-described errors (such as syringe swaps) but also by some new errors related to recently introduced anaesthetic equipment, such as electronic anaesthesia workstations.

Measurement of charged-particle stopping in warm dense plasma

We measured the stopping of energetic protons in an isochorically heated solid-density Be plasma with an electron temperature of ∼32  eV, corresponding to moderately coupled [(e^{2}/a)/(k_{B}T_{e}+E_{F})∼0.3] and moderately degenerate [k_{B}T_{e}/E_{F}∼2] "warm-dense matter" (WDM) conditions. We present the first high-accuracy measurements of charged-particle energy loss through dense plasma, which shows an increased loss relative to cold matter, consistent with a reduced mean ionization potential. The data agree with stopping models based on an ad hoc treatment of free and bound electrons, as well as the average-atom local-density approximation; this work is the first test of these theories in WDM plasma.

Solid-organ transplantation in older adults: current status and future research

An increasing number of patients older than 65 years are referred for and have access to organ transplantation, and an increasing number of older adults are donating organs. Although short-term outcomes are similar in older versus younger transplant recipients, older donor or recipient age is associated with inferior long-term outcomes. However, age is often a proxy for other factors that might predict poor outcomes more strongly and better identify patients at risk for adverse events. Approaches to transplantation in older adults vary across programs, but despite recent gains in access and the increased use of marginal organs, older patients remain less likely than other groups to receive a transplant, and those who do are highly selected. Moreover, few studies have addressed geriatric issues in transplant patient selection or management, or the implications on health span and disability when patients age to late life with a transplanted organ. This paper summarizes a recent trans-disciplinary workshop held by ASP, in collaboration with NHLBI, NIA, NIAID, NIDDK and AGS, to address issues related to kidney, liver, lung, or heart transplantation in older adults and to propose a research agenda in these areas.

System-based factors influencing intraoperative decision-making in rectal cancer by surgeons: an international assessment

AIM

Sound surgical judgement is the goal of training and experience; however, system-based factors may also colour selection of options by a surgeon. We analysed potential organizational characteristics that might influence rectal cancer decision-making by an experienced surgeon.

METHOD

One hundred and seventy-three international centres treating rectal cancer were invited to participate in a survey assessment of key treatment options for patients undergoing curative rectal-cancer surgery. The key organizational characteristics were analysed using multivariate methods for association with intra-operative surgical decision-making.

RESULTS

The response rate was 71% (123 centres). Sphincter-saving surgery was more likely to be performed at university hospitals (OR=3.63, P=0.01) and by high-caseload surgeons (OR=2.77 P=0.05). A diverting stoma was performed more frequently in departments with clinical audits (OR=3.06, P=0.02), and a diverting stoma with coloanal anastomosis was more likely in European centres (OR=4.14, P=0.004). One-stage surgery was less likely where there was assessment by a multidisciplinary team (OR=0.24, P=0.02). Multivariate analysis showed that university hospital, clinical audit, European centre, multidisciplinary team and high caseload significantly impacted on surgical decision-making.

CONCLUSION

Treatment variance of rectal cancer surgeons appears to be significantly influenced by organizational characteristics and complex team-based decision-making. System-based factors may need to be considered as a source of outcome variation that may impact on quality metrics.

Penetration of efavirenz into the male genital tract: drug concentrations and antiviral activity in semen and blood of HIV-1-infected men

Efavirenz is a potent non-nucleoside reverse transcriptase inhibitor, licensed for the treatment of HIV-1. Data on sanctuary site penetration are limited. Therefore, we measured efavirenz concentrations in the blood and semen of 19 HIV-1-positive men and found concentrations in seminal plasma averaged 10% of those in blood plasma. Furthermore, seminal plasma viral loads were suppressed by 24 weeks of therapy in all patients. These data suggest that efavirenz-containing regimens have antiviral activity within the male genital tract.

Antiretroviral drug concentrations in semen of HIV-infected men: differential penetration of indinavir, ritonavir and saquinavir

Variable drug penetration of antiretroviral drugs into the genital tract may contribute to the differential evolution of HIV and the emergence of drug resistance. This, in turn, may have an impact on the sexual transmission of resistant HIV in patients treated with antiretroviral drugs. We have measured concentrations of the HIV-1 protease inhibitors indinavir, ritonavir and saquinavir in the blood plasma (BP) and seminal plasma (SP) of 23 HIV-1-positive men. Forty-five time-matched blood and semen samples were obtained. SP concentrations of indinavir exceeded the EC95 of indinavir, corrected for protein binding, of 42 ng/mL at all time intervals. In contrast, the median ritonavir and saquinavir SP concentrations were below the relevant EC95 at all times post drug ingestion. The median SP:BP concentration ratios for indinavir were 0.6, 0.8 and 1.4, respectively, at 0-2, 2-6 and 6-8 h post-drug ingestion. In contrast, the median SP:BP concentration ratios at 0-3, 3-9 and 9-12 h post-drug ingestion were <0.02, <0.04 and <0.04, respectively, for both ritonavir and saquinavir. These differences justify further study of HIV-1 evolution and development of resistance in the genital tract of men taking these anti-HIV drugs.

The UKCC's Scope of Professional Practice--some implications for health care delivery

AIMS

The research reported here is part of a larger study commissioned by the United Kingdom Central Council for Nursing, Midwifery and Health Visiting (UKCC) to analyse and understand the impact of the Scope of Professional Practice (Scope) on the practice of nursing, midwifery and health visiting. The data in this paper relate to attitudes about, and perceptions of Scope among a variety of stakeholders.

BACKGROUND

This research provided a valuable opportunity to explore the essence of Scope and the ways in which it can enable nurses, midwives and health visitors to adapt to growing or changing health care needs. The findings contribute to this debate, by drawing on the knowledge and experience of the key groups involved in the change process.

METHOD

The study utilized several approaches, tailored to meet the requirements of each phase. In this (the final) phase a structured questionnaire was sent to different groups of stakeholders.

FINDINGS AND CONCLUSIONS

The stakeholders displayed considerable interest in the development of innovative systems for delivering nursing and midwifery care, provided that the necessary safeguards and support were in place. Scope was seen as a valuable way of optimizing the skills and contribution of nurses, midwives and health visitors.

Recognising advancing nursing practice: evidence from two observational studies

Debates over title, grades and relationships across the profession has tended to dominate the literature in advancing nursing practice. Fewer research projects have attempted to study the activities of nurses who are designated as undertaking advancing nursing roles. One study evaluating Masters courses for Clinical Nursing Practice and a second addressing the impact of the 'Scope of Professional Practice' (United Kingdom Central Council for Nursing, Midwifery & Health Visiting, 1992) document by this team of authors afforded these research opportunities. In this paper empirical data from 'reflective' observation with 19 nurses (including midwives and health visitors) are presented to illustrate the range and type of functions undertaken by a small group of practitioners developing their practice. A number of characteristic features emerged. Assessment of individual and group needs, positive motivation to constantly improve practice, inter-disciplinary and cross agency working for planned change and an ability to identify and prioritize service requirements were recognised in these nurses' roles. Certain personal attributes were seen to be essential for successful role development such as confidence, commitment and problem solving powers combined with a positive working environment and supportive managers.

Evaluation of the role of the Parkinson's disease nurse specialist

A one year follow up study of 108 randomised patients with Parkinson's disease at three centres was performed to investigate differences between care provided by the hospital based Parkinson's disease nurse specialist (PDNS) compared with the Consultant Neurologist (control). Only two (out of 22) differences were found where physical functioning and general health improved more in the control group. Provision of PDNS' for patients with Parkinson's disease cannot therefore be recommended solely on cost-effectiveness grounds because of similar outcomes but increased costs associated with the PDNS providing additional care. However medical and nursing specialists valued their complimentary expertise, and patient and carers responses to consultations also reflect that PDNS's have particular contributions. Aspects of care most valued by patients and carers and consultation interactions are discussed.

Isolation and characterization of a human neutrophil aggregation defective mutant of Fusobacterium nucleatum

Fusobacterium nucleatum is known to adhere to human polymorphonuclear neutrophils (PMNs) and cause them to aggregate. In this study, we isolated a spontaneously occurring aggregation defective (AGG(-)) mutant and this mutant will be used for future study of the interactions between this bacterium and human PMN. Genomic DNA fingerprinting by random-primed polymerase chain reaction method revealed a difference between the parent strain and the AGG(-) mutant. This mutant also showed an altered phenotype in both microbicidal and phagocytic assays, suggesting that the bacterial factor involved in the aggregation may also be very important for the phagocytosis and, subsequently, the killing by human PMNs. Further study of this mutant may help to clarify the molecular mechanisms of the interaction between this pathogen and human PMNs.

Elevated glutathione biosynthetic capacity in the chloroplasts of transgenic tobacco plants paradoxically causes increased oxidative stress

Glutathione (GSH), a major antioxidant in most aerobic organisms, is perceived to be particularly important in plant chloroplasts because it helps to protect the photosynthetic apparatus from oxidative damage. In transgenic tobacco plants overexpressing a chloroplast-targeted gamma-glutamylcysteine synthetase (gamma-ECS), foliar levels of GSH were raised threefold. Paradoxically, increased GSH biosynthetic capacity in the chloroplast resulted in greatly enhanced oxidative stress, which was manifested as light intensity-dependent chlorosis or necrosis. This phenotype was associated with foliar pools of both GSH and gamma-glutamylcysteine (the immediate precursor to GSH) being in a more oxidized state. Further manipulations of both the content and redox state of the foliar thiol pools were achieved using hybrid transgenic plants with enhanced glutathione synthetase or glutathione reductase activity in addition to elevated levels of gamma-ECS. Given the results of these experiments, we suggest that gamma-ECS-transformed plants suffered continuous oxidative damage caused by a failure of the redox-sensing process in the chloroplast.

Systemic signaling and acclimation in response to excess excitation energy in Arabidopsis

Land plants are sessile and have developed sophisticated mechanisms that allow for both immediate and acclimatory responses to changing environments. Partial exposure of low light-adapted Arabidopsis plants to excess light results in a systemic acclimation to excess excitation energy and consequent photooxidative stress in unexposed leaves. Thus, plants possess a mechanism to communicate excess excitation energy systemically, allowing them to mount a defense against further episodes of such stress. Systemic redox changes in the proximity of photosystem II, hydrogen peroxide, and the induction of antioxidant defenses are key determinants of this mechanism of systemic acquired acclimation.

A new in vitro model to study interaction between whole blood and biomaterials. Studies of platelet and coagulation activation and the effect of aspirin

We have developed a versatile in vitro chamber model with a double purpose: first, to be able to study mechanisms of bio-incompatibility, and, second, to test biomaterials at all levels of interactions, in whole blood. The use of biomaterials in the form of microscope slides as walls in the chamber makes it possible to analyse both the biomaterial surface with regard to protein and cell binding, as well as the molecular events taking place in the fluid. Incubation of blood in the chamber, for 60 min at 37 degrees C resulted in the rapid binding of complement and coagulation proteins and of leukocytes and platelets to polyvinylchloride (PVC) slides. The cells formed a layer which more or less covered the underlying surface. Unlike complement activation, as reflected by soluble C3a and C5b-9, the thrombin-antithrombin formation was completely nullified in cell-depleted plasma. Despite the fact that thrombin-antithrombin generation was also negligible in platelet-rich plasma, inhibition of platelet aggregation on the material surface with aspirin resulted in suppressed generation of thrombin antithrombin complexes. Taken together, the coagulation activation in the chamber was dependent on the presence of blood cells which suggests that bound/aggregated platelets initiate a sequence of events involving leukocytes that results in coagulation activation.

New Zealand health reforms: effect on ophthalmic practice

Are specialized ophthalmic units with inpatient facilities going to disappear in the New Zealand public health system? We have entered the era of cost containment, business methodologies, bench marking, day case surgery, and technologic advances. The dilemma for nursing is maintenance of a skill base with dwindling clinical practice areas.

Efficacy of a triclosan/NaF dentifrice in the control of plaque and gingivitis and concurrent oral microflora monitoring

PURPOSE

To compare the effect of a dentifrice containing 0.3% triclosan and 1100 ppm fluoride and a control dentifrice containing 1100 ppm fluoride on plaque, gingiva and the oral microflora in a long-term study simulating clinical usage.

MATERIALS AND METHODS

159 subjects entered the clinical study and 80 were randomly selected to participate in the microbiological evaluation. 71 subjects completed the detailed evaluation of the oral microflora after 6 months use. Plaque was collected at baseline, 3 months, and 6 months, and examined by darkfield microscopy, Gram stain, immunofluorescence, and selective and non-selective media. Changes in antimicrobial susceptibilities were determined for the first 6-month period and for 6 months post-therapy for 68 subjects who completed the entire study. Susceptibilities of whole plaque samples and MIC values for two pre-designated common plaque organisms, A. viscosus and V. parvula were performed.

RESULTS

Multivariate ANOVA and non-parametric analyses revealed no statistical differences for any factor tested. No detrimental shifts were found in either; (1) the compositional make up of the normal flora, (2) the periodontopathic or cariogenic flora, or (3) the opportunistic flora in either group of dentifrice users. Both treatments resulted in decreases in Gram positive cocci over time. There was a reduction in spirochetes in the triclosan/fluoride group as compared to the control group. No overgrowth in opportunists, periodontal pathogens, or cariogenic flora was found in either group. No increase in the proportion of the whole plaque flora resistant to triclosan was found nor was an increase in the MIC values of either A. viscosus or V. parvula in either group. Overall, there appeared to be a general decrease in plaque bacteria in both groups over the course of the experiment.

Preventive health care for mentally ill women

Utilization of preventive medical care was compared for two low-income groups--47 women with serious mental illness in an urban mental health center and 17 women patients at a primary care center. Appropriate preventive care was defined as at least one physical examination, a Pap test, and a breast examination in the past five years and a mammogram if the patient was over age 40. Receipt of preventive care by women in both settings was similar. Histories of physical and sexual abuse were prevalent in both groups, and a history of abuse was associated with less frequent receipt of preventive care. Results indicate that procedures to identify and provide services to women with abuse histories should be further developed.

Simultaneous targeting of pea glutathione reductase and of a bacterial fusion protein to chloroplasts and mitochondria in transgenic tobacco

N-terminal presequences from cDNAs encoding mitochondrion- or chloroplast-specific proteins are able, with variable efficiencies, to target preproteins to their respective organelles. In the few cases studied in which a nuclear-encoded protein is found in both these organelles, each compartment-specific isoform is encoded by a separate gene. Glutathione reductase (GR) from peas is encoded by a single nuclear gene and yet GR is distributed between chloroplasts, mitochondria and the cytosol. Previous sequence analysis of a full-length GR cDNA revealed the presence of a putative plastid transit peptide. However, expression of this cDNA in transgenic tobacco resulted in substantially elevated GR activities in both chloroplasts and mitochondria in four independent lines examined. There was no effect on expression of the endogenous tobacco GR genes. Replacement of the GR presequence with presequences from pea rbcS (chloroplast) and Nicotiana plumbaginifolia Mn-SOD (mitochondrion) resulted in targeting of GR only into the appropriate organelle. Expression of a fusion protein between the amino terminal region of GR and phosphinothricin acetyl transferase resulted in targeting of the foreign protein to chloroplasts and mitochondria. Thus, the pea GR presequence is capable of co-targeting this enzyme or a foreign protein to chloroplasts and mitochondria in vivo. This is the first example of co-targeting by a higher plant preprotein.

Cholesterol-lowering effects of soluble-fiber cereals as part of a prudent diet for patients with mild to moderate hypercholesterolemia

Soluble-fiber breakfast cereals were examined for their cholesterol-lowering ability in 58 male patients with mild to moderate hypercholesterolemia in a randomized, double-blind, placebo-controlled study. Patients followed a step 1 diet for a minimum of 6 wk, then were randomly assigned to groups incorporating either corn flakes or one of two soluble-fiber cereals (pectin enriched or psyllium enriched) in the diet for an additional 6 wk. During the diet-only phase, total cholesterol dropped 3.8%. During the cereal-plus-diet phase, total and LDL cholesterol values of the pectin-enriched cereal group dropped an additional 2.1% (P = 0.243) and 3.9% (P = 0.16), respectively, and they dropped 5.9% (P = 0.005) and 5.7% (P = 0.034), respectively, in the psyllium-enriched cereal group. During the cereal-plus-diet phase, no significant effects on HDL cholesterol, triglyceride, or body weight were found within or between any cereal groups. These results support use of soluble-fiber cereals as an effective and well-tolerated part of a prudent diet in the treatment of mild to moderate hypercholesterolemia.

Agrobacterium - and microprojectile - mediated viral DNA delivery into barley microspore-derived cultures

Anther cultures of barley (Hordeum vulgare L. var. "Igri") were used as targets for Agrobacterium-mediated DNA transfer and direct DNA uptake by particle bombardment. A wheat dwarf virus construct which can replicate to a high copy number in cereal cells provided a sensitive marker for successful DNA delivery. Although DNA delivery was achieved using both procedures, particle bombardment gave more reproducible and higher levels of infection. The ability to deliver DNA into cereal cells which have a high regeneration capacity may provide a route for stable transformation.

Cholesterol-lowering effects of psyllium hydrophilic mucilloid. Adjunct therapy to a prudent diet for patients with mild to moderate hypercholesterolemia

Psyllium hydrophilic mucilloid was examined for its ability to lower serum cholesterol levels in hypercholesterolemic patients. Seventy-five patients with mild to moderate hypercholesterolemia were evaluated in this randomized, double-blind, placebo-controlled parallel study. Patients were treated with a Step I diet for 12 weeks before receiving placebo or 3.4 g of psyllium (equivalent to 1 teaspoon) three times per day for 8 weeks. Compared with placebo, psyllium achieved an additional 4.8% reduction in total cholesterol level, 8.2% reduction in low-density lipoprotein cholesterol level, and 8.8% reduction in apolipoprotein B level. Psyllium did not significantly affect blood pressure or levels of high-density cholesterol, triglycerides, serum glucose, or iron. Reported adherence to diet and treatment was excellent, and no significant adverse side effects were noted. These results indicate psyllium hydrophilic mucilloid is an effective and well-tolerated adjunct to diet in the management of mild to moderate hypercholesterolemia.

Effects of immunization with B. macacae on induced periodontitis--preliminary findings

This preliminary study examined the effects of immunization with Bacteroides macacae, the monkey equivalent of the human species of B. gingivalis on ligature-induced periodontitis. During a 12 week immunization period, 8 out of the 12 Macacae fasicularis monkeys were immunized weekly with B. macacae washed cells and 4 were sham-immunized with saline. At the same time, all were scaled and pumiced weekly to establish gingival health. Following this period, the mandibular first molars were ligated in 8 out of the 12 monkeys to induce periodontitis. The immunized, ligated experimental group, the ligated, sham-immunized control group, and the immunized, non-ligated control group were then followed for a 6 months ligation period while plaque was allowed to accumulate. Gingival indices, attachment levels, pocket depths, plaque indices, radiographs, serum and crevicular fluid antibodies and subgingival bacteria were assessed. Immunization led to elevated antibody levels to B. macacae while ligation increased plaque, gingival inflammation, and bone loss. Following the 6 month ligation period, B. macacae comprised 1.7% of the cultivable flora in the immunized, non-ligated monkeys, 2.1% in the immunized, ligated monkeys, and 5.6% in the sham-immunized, ligated monkeys. Similar differences between the immunized, ligated and and the sham-immunized, ligated groups were not seen for B. intermedius, nor B. melaninogenicus. These results suggest a heightened humoral response to B. gingivalis reduces subgingival re-colonization by this organism and modulates the course of ligature-induced periodontitis.

Microbiological and immunological studies of adult periodontitis in patients with noninsulin-dependent diabetes mellitus

The subgingival microflora and serum antibody response was examined in periodontitis patients with noninsulin-dependent diabetes mellitus (NIDDM), impaired glucose tolerance (IGT), and normal glucose tolerance (NGT). The predominant cultivable microflora was determined for subgingival plaque sampled from two deep periodontal pockets in each of eight adult periodontitis patients with NIDDM. Indirect immunofluorescence for Bacteroides intermedius, Bacteroides gingivalis, and Haemophilus actinomycetemcomitans was used to examine these same samples as well as 186 additional subgingival plaque samples from 47 patients with moderate to severe generalized periodontitis including 25 subjects with NIDDM, six subjects with IGT, and 16 subjects with NGT. Serum antibody levels to 13 microorganisms including seven oral bacterial species and one nonoral control species were measured by enzyme-linked immunosorbent assays (ELISA) in 377 subjects including 84 normal subjects without periodontal disease, 112 normal subjects with periodontitis, 19 periodontally normal subjects with IGT, 65 periodontitis patients with IGT, 15 periodontally normal subjects with NIDDM, and 82 periodontitis patients with NIDDM. Three hundred eighty-two bacterial isolates were recovered from the eight patients. B. intermedius was the most frequently isolated microorganism constituting 16% of the total isolates followed by Wolinella recta and B. gingivalis, which each accounted for 13% of the total. Streptococcus sanguis was the most prevalent microorganism, which was found in 75% of the sites. Subgingival plaque samples examined by immunofluorescence demonstrate a high prevalence of black-pigmented Bacteroides and suggest that the proportion of B. gingivalis but not B. intermedius is higher in NIDDM with periodontitis than in other groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Cement coating of osteoarticular allografts in rats to prevent the immune response

Recently, more attention is being paid to the treatment of the articular surface defect in the young, active individual. Resurfacing or "shell" allografts are being considered as one of the alternatives for treatment. The immune response by the host may be the chief obstacle to the successful use of fresh osteoarticular allografts. Since proteins on the surfaces of allograft bone cells are considered to be the principal antigens eliciting the immune response, we hypothesized that mechanical masking of these cells by a biodegradeable blocking agent might prevent the immune response. Osteoarticular allografts of the distal femur were performed in rats and the cut surfaces of the graft were coated with cement before implantation. In a preliminary experiment, six biodegradeable cement materials were tried (bone wax, zinc polycarboxylate, collodion, fibrin adhesive, zinc oxide, and isobutyl-cyanoacrylate). Of these, the zinc oxide cement and isobutyl-cyanoacrylate were effective in inhibiting the immune response observed in control rat distal femur allografts. A second experiment was performed using nine rats with zinc oxide and nine rats with isobutyl-cyanoacrylate cements. These were compared with 20 control rats that had allografts without cement coating. Eighteen of the control rats (90%) developed an immune response, while only 22% (2/9) of the rats with zinc oxide coating and 33% (3/9) of the rats with isobutylcyanoacrylate developed an immune response. In a third experiment distal femur allografts were performed in 13 rats using only the liquid component of the zinc oxide cement.(ABSTRACT TRUNCATED AT 250 WORDS)

Cervical rheumatoid arthritis: value of flexion and extension views in imaging

The magnetic resonance (MR) imaging findings in the cervical spines of eight patients with long-standing polyarticular rheumatoid arthritis were reviewed. Three pathologic conditions were readily demonstrated: anterior atlantoaxial subluxation (n = 6), atlantoaxial impaction (n = 6), and subaxial subluxation (n = 6). An abnormal soft-tissue signal was noted in the preodontoid space in six patients; this signal was thought to represent the associated inflammatory mass. MR imaging was useful not only for depicting the bony abnormalities in the cervical spine that are associated with rheumatoid arthritis, but also can directly show the effect of the disease process on the spinal cord and brain stem.

Release of estradiol from fetal bovine serum by rat thymus, spleen, kidney, lung and lung macrophage cultures

High levels of estradiol (E2) were detected by radioimmunoassay (RIA) in supernatants of rat thymus and spleen, kidney, lung and lung macrophages cultured in the presence of fetal bovine serum(FBS). A competitive inhibitor of E2 synthesis and no effect on the production of E2 by thymic cultures. Acid hydrolysis of estrogen conjugates in FBS released enough free E2 to account for the high level found in culture supernatants. Removal of free estrogens and estrogen conjugates by charcoal stripping the serum before addition to media of rat tissues by hydrolysis of estrogen conjugates in FBS.

Eubacterium saburreum and Veillonella parvula: a symbiotic association or oral strains

A cocci-filament association was discovered in bacterial cultural studies of a subgingival plaque sample. Components were isolated and identified as Veillonella parvula and Eubacterium saburreum. A E. saburreum cell-associated material consisting of approximately 25% glucose and 70% protein was found which may play a role in the adherence of V. parvula to this filament. Acid end product analysis via gas liquid chromatography showed an uptake of lactic and succinic acids by V. parvula resulting in increased levels of acetic, propionic and n-butyric acids in mixed culture of the E. saburreum and the V. parvula strains. The ability of E. saburreum to adhere to nichrome wire and to glass surfaces as well as the secondary plaque forming ability of V. parvula indicates that these organisms may play a role in the maturation of human dental plaque.