Awareness, attitudes, and practices on meningococcal serogroup B vaccination in the United States among parents of older adolescents and among young adults

OBJECTIVE

Meningococcal serogroup B (MenB) vaccination is recommended by the Advisory Committee on Immunization Practices (ACIP) for adolescents and young adults 16-23-years-old under shared clinical decision-making (SCDM). However, MenB vaccination coverage in this population remains low in the United States (US). We investigated the awareness, attitudes, and practices regarding MenB disease and vaccination among parents of 16-18-year-old older adolescents and among 19-23-year-old young adults.

METHODS

An online survey was conducted in September-October 2022 among parents of older adolescents and among young adults recruited from a US-based patient panel.

RESULTS

There were 606 total participants, including parents of MenB-vaccinated (n = 151) and non-vaccinated (n = 154) adolescents, and also MenB-vaccinated (n = 150) and non-vaccinated (n = 151) young adults. Non-vaccinated cohorts reported low awareness of MenB disease (58.3-67.5%) and vaccination (49.7-61.0%), though awareness was higher among non-vaccinated parents. However, all cohorts reported high interest in learning more about MenB disease and vaccination. Vaccinated cohorts relied on primary care providers (PCPs) to initiate MenB vaccination conversation and had a low awareness of SCDM at 35.1-45.3%, though those aware of SCDM were more likely to participate in decision-making. Barriers to MenB vaccination included lack of PCP recommendation, vaccine side effects, and uncertainty about vaccination need.

CONCLUSIONS

There are gaps in awareness of MenB disease, vaccination, and SCDM among parents and patients in the US, resulting in missed opportunities for discussing and administering MenB vaccination. Targeted education on MenB and vaccination recommendations may increase these opportunities and improve MenB vaccination awareness and initiation.

Use of expanded Neisseria meningitidis serogroup B panels with the serum bactericidal antibody assay for the evaluation of meningococcal B vaccine effectiveness

INTRODUCTION

Neisseria meningitidis serogroup B (NmB) antigens are inherently diverse with variable expression among strains. Prediction of meningococcal B (MenB) vaccine effectiveness therefore requires an assay suitable for use against large panels of epidemiologically representative disease-causing NmB strains. Traditional serum bactericidal antibody assay using exogenous human complement (hSBA) is limited to the quantification of MenB vaccine immunogenicity on a small number of indicator strains.

AREAS COVERED

Additional and complementary methods for assessing strain coverage developed previously include the Meningococcal Antigen Typing System (MATS), Meningococcal Antigen Surface Expression (MEASURE) assay, and genotyping approaches, but these do not estimate vaccine effectiveness. We provide a narrative review of these methods, highlighting a more recent approach involving the hSBA assay in conjunction with expanded NmB strain panels: hSBA assay using endogenous complement in each vaccinated person's serum (enc-hSBA) against a 110-strain NmB panel and the traditional hSBA assay against 14 (4 + 10) NmB strains.

EXPERT OPINION

The enc-hSBA is a highly standardized, robust method that can be used in clinical trials to measure the immunological effectiveness of MenB vaccines under conditions that mimic real-world settings as closely as possible, through the use of endogenous complement and a diverse, epidemiologically representative panel of NmB strains.

Can tibio-femoral kinematic and kinetic parameters reveal poor functionality and underlying deficits after total knee replacement? A systematic review

BACKGROUND

Extensive efforts have been made to understand joint kinematics and kinetics in total knee arthroplasty (TKA) in subjects with satisfactory outcomes during daily functional activities and clinical tests, but it remains unclear whether such movement characteristics hold the potential to indicate the underlying aetiology of unsatisfactory or bad TKA outcomes.

PURPOSE

To investigate which kinematic and kinetic parameters assessed during passive clinical tests and functional activities of daily living are associated with poor functionality and underlying deficits after total knee replacement.

METHODS

We focused on studies characterizing the kinematic or kinetic parameters of the knee joint that are associated with poor clinical outcome after TKA. Seventeen articles were included for the review, and kinematic and kinetic data from 719 patients with minimal follow up of 6 months were extracted and analyzed.

RESULTS

Passive posterior translation at 90°flexionexhibited good potential for differentiating stable and unstable TKAs. Anterior-posterior (A-P) translation of the medial condyle at 0-30° and 30-60° flexion, A-P translation of the lateral condyle at 60-90°during closed chain exercises, as well asknee extension moment during stair ascent and descent, knee abduction moment during stair descent, knee internal rotation moment and plantar flexion moment during walking, 2ndpeak ground reaction force during stair ascent and walkingshowed the greatest promise as functional biomarkers for a dissatisfied/poor outcome knee after TKA.

CONCLUSION

In this study, we systematically reviewed the state-of-the-art knowledge of kinematics and kinetics associated with functional deficits, and found 11 biomechanical parameters that showed promise for supportingdecision making in TKA.

Expert opinion on the way forward for improving maternal influenza vaccination in India

INTRODUCTION

: Rates of maternal vaccination against influenza are extremely low in India. An expert panel of obstetric-gynecologists and pediatricians met to develop consensus-based recommendations for improving awareness of the benefits of influenza vaccination during pregnancy in India.

AREAS COVERED

: The group discussed experiences of influenza infection in pregnancy and infancy before focusing on maternal vaccination practices in India, including the degree of communication between obstetric-gynecologists and pediatricians and opinions on optimal timing for vaccination. The impact of inconsistent vaccine prescription practices by healthcare providers was discussed, as well as current clinical recommendations on maternal influenza vaccination.

EXPERT OPINION

: Although clinical evidence demonstrates the benefit of maternal influenza vaccination in any trimester, influenza vaccination is not widely accepted in India as an integral part of antenatal care. There is a lack of familiarity among obstetricians of clinical guidelines on maternal influenza vaccination. This can be addressed with an education campaign targeting obstetricians and other providers of maternal healthcare. With variable influenza seasons between regions in India, common vaccine stock shortages, and data suggesting influenza vaccination is feasible anytime in pregnancy, all opportunities to offer vaccination to this high-risk group for severe influenza disease should be considered.

Health economic assessment of a rabies pre-exposure prophylaxis program compared with post-exposure prophylaxis alone in high-risk age groups in the Philippines

OBJECTIVES

Once symptoms appear, rabies is almost always fatal and accounts for 200-300 deaths annually in the Philippines. Available rabies vaccines can be administered either in pre- exposure prophylaxis (PrEP) or post-exposure prophylaxis (PEP). After exposure, PrEP-immunized individuals require fewer doses of PEP and no rabies immunoglobulin.

METHODS

A static decision-tree model was developed to assess cost-effectiveness of a PrEP+PEP program vs PEP alone. Philippines-specific data for people seeking medical advice at the Research Institute for Tropical Medicine between July 2015 and June 2016 were used in the model, together with data from published literature.

RESULTS

Over a 20-year period, in a cohort of 1 million 5-year-old children in the Philippines, PrEP+PEP was expected to prevent 297 deaths compared with PEP alone. From both payer and societal perspectives, the resulting incremental cost-effectiveness ratios were 36 035 (US$759; 2016 US$ conversion) and 18 663 (US$393) Philippine Pesos (PHP) - quality-adjusted life-years gained - respectively, which are both below the willingness-to-pay threshold of PHP140 255 (US$2 953).

CONCLUSION

These data suggest that a universal PrEP program targeting 5-year-olds would be cost-effective in the Philippines.

Vaccinating pregnant women against influenza needs to be a priority for all countries: An expert commentary

BACKGROUND

In 2012, the World Health Organization recommended influenza vaccination for all pregnant women worldwide and the prioritisation of pregnant women in national influenza vaccination programmes. Nevertheless, vaccination rates in pregnant women often remain much lower than national targets.

OBJECTIVES

To assess the benefits and risks associated with influenza infection and vaccination during pregnancy, and to consider obstacles that work against influenza vaccine uptake during pregnancy.

RESULTS

There is strong evidence that maternal and foetal outcomes can be compromised if women develop influenza infections during pregnancy. Influenza vaccines have been administered to millions of pregnant women and have demonstrated benefits in terms of disease prevention in mothers and their infants. There is a consensus amongst several recommending authorities that influenza vaccines may be safely administered during all stages of pregnancy. Healthcare professionals are recognised as the most important influencers of vaccine uptake, being well placed to recommend vaccination and directly address safety concerns.

CONCLUSIONS

Despite data supporting the value of influenza vaccination during pregnancy, vaccine uptake remains low globally. Low uptake appears to be largely due to ineffective communication with pregnant women about the risks and benefits of influenza vaccination. A graphical abstract is available online.

Post-exposure prophylaxis (PEP) for rabies with purified chick embryo cell vaccine: a systematic literature review and meta-analysis

INTRODUCTION

Fifteen million people each year receive post-exposure prophylaxis (PEP) to prevent rabies, yet the disease remains neglected and highly under-reported.

AREAS COVERED

In this systematic literature review, we assessed the immunogenicity, efficacy, and safety of a purified chick embryo cell-culture rabies vaccine (PCECV) for PEP against rabies by intramuscular (IM) or intradermal (ID) administration. We performed meta-analyses to compare immunogenicity according to the route of vaccine administration, study population, and PEP regimen, such as number of doses, and concomitant rabies immunoglobulin.

EXPERT COMMENTARY

There were 54 estimates of immune responses to vaccination, which showed that in the overall population, after starting PEP with PCECV by the IM or ID route (≥2.5 IU per dose), almost all individuals had rabies virus neutralizing antibody (RVNA) titers above the World Health Organization (WHO) recommended serological threshold for an adequate immune response to vaccination (RVNA ≥0.5 IU/ml by day 14). In the overall population, PCECV had an acceptable safety profile. However, given that there are 59,000 human rabies deaths reported annually, the challenge is to improve access to PCECV for PEP against human rabies.

Heterogeneity of Rabies Vaccination Recommendations across Asia

Asian countries bear the greatest burden of the disease, with a majority (59%) of rabies-related deaths occurring in Asia. In order to promote best practices, we summarized national human vaccination guidelines across this region, to highlight differences and similarities and to discuss the aspects that would benefit from updates. National management guidelines for rabies were retrieved from various sources to extract information on rabies pre- and post-exposure prophylaxis (PrEP, and PEP), booster vaccination, and route of administration. Rabies guidelines recommendations for wound management and PrEP across Asia are broadly aligned to the World Health Organization (WHO) guidelines. For PEP, the 5-dose Essen, and the 4-dose Zagreb are the regimens of choice for intramuscular (IM), and the Thai Red Cross regimen for intradermal (ID), administration. Several national guidelines have yet to endorse ID vaccine administration. Most guidelines recommend rabies immunoglobulin in category III exposures. Booster recommendations are not included in all guidelines, with limited clarity on booster requirement across the spectrum of risk of rabies exposure. In conclusion, national recommendations across Asian countries differ and while some guidelines are closely aligned to the WHO recommendations, resource-saving ID administration and use of rational abbreviated schedules have yet to be endorsed.

Comparison of the immunogenicity and safety of the purified chick embryo cell rabies vaccine manufactured in India and Germany: A randomized, single blind, multicentre, phase IV clinical study

This phase IV, single blind study assessed the immunogenicity and safety of India-manufactured purified chick embryo cell rabies vaccine (PCECV), compared with a German-manufactured batch obtained by the same production process. A total of 340 participants enrolled at 2 study sites in India were randomized (1:1:1:1) in 4 groups to receive a 5-dose Essen regimen with either 1 of the 3 Indian batches (PCECV-I) or the German batch (PCECV-G), administered on Days (D) 0, 3, 7, 14 and 30. The lot-to-lot consistency of PCECV-I batches in terms of induced immune response at D14 was demonstrated. The immune response elicited by PCECV-I was shown to be non-inferior to that induced by PCECV-G, as the lower limit of the 95% confidence interval for the ratio (PCECV-I/PCECV-G) of rabies virus neutralising antibody (RVNA) geometric mean concentrations was higher than 0.5 at D14. At least 96% of participants developed adequate RVNA concentrations (≥ 0.5 IU/mL) by D14 and all achieved RVNA concentrations ≥ 0.5 IU/mL by D90. RVNA levels were comparable across all groups throughout the entire study. Solicited local and general symptoms had a similar incidence in all groups. Unsolicited adverse events (AEs) were reported by 11% of participants. Only 1 serious AE (leg fracture) was reported and was not related to vaccination. No deaths and no rabies cases were recorded during the 90 days of observation. The study showed that the 3 PCECV-I and the PCECV-G batches induced a similar immune response and had a comparable safety profile when administered according to a 5-dose schedule.

Cervical joint position sense in neck pain. Immediate effects of muscle vibration versus mental training interventions: a RCT

BACKGROUND

Impaired cervical joint position sense is a feature of chronic neck pain and is commonly argued to rely on abnormal cervical input. If true, muscle vibration, altering afferent input, but not mental interventions, should have an effect on head repositioning acuity and neck pain perception.

AIM

The aim of the present study was to determine the short-term effects of neck muscle vibration, motor imagery, and action observation on cervical joint position sense and pressure pain threshold in people with chronic neck pain.

DESIGN

Forty-five blinded participants with neck pain received concealed allocation and were randomized in three treatment groups. A blinded assessor performed pre- and post-test measurement.

SETTING

Patients were recruited from secondary outpatient clinics in the southwest of Germany.

POPULATION

Chronic, non specific neck pain patients without arm pain were recruited for this study.

METHODS

A single intervention session of 5 minutes was delivered to each blinded participant. Patients were either allocated to one of the following three interventions: (1) neck muscle vibration; (2) motor imagery; (3) action observation. Primary outcomes were cervical joint position sense acuity and pressure pain threshold. Repeated measures ANOVAs were used to evaluate differences between groups and subjects.

RESULTS

Repositioning acuity displayed significant time effects for vibration, motor imagery, and action observation (all P<0.05), but revealed no time*group effect. Pressure pain threshold demonstrated a time*group effect (P=0.042) as only vibration significantly increased pressure pain threshold (P=0.01).

CONCLUSION

Although motor imagery and action observation did not modulate proprioceptive, afferent input, they nevertheless improved cervical joint position sense acuity. This indicates that, against the common opinion, changes in proprioceptive input are not prerequisite to improve joint repositioning performance. However, the short-term applications of these cognitive treatments had no effect on pressure pain thresholds, whereas vibration reduced pressure pain thresholds. This implies different underlying mechanisms after vibration and mental training.

CLINICAL REHABILITATION IMPACT

Mental interventions were effective in improving cervical joint position sense and are easy to integrate in rehabilitation regimes. Neck muscle vibration is effective in improving cervical joint position sense and pressure pain thresholds within 5 minutes of application.

Vaccine Adjuvants: from 1920 to 2015 and Beyond

The concept of stimulating the body's immune response is the basis underlying vaccination. Vaccines act by initiating the innate immune response and activating antigen presenting cells (APCs), thereby inducing a protective adaptive immune response to a pathogen antigen. Adjuvants are substances added to vaccines to enhance the immunogenicity of highly purified antigens that have insufficient immunostimulatory capabilities, and have been used in human vaccines for more than 90 years. While early adjuvants (aluminum, oil-in-water emulsions) were used empirically, rapidly increasing knowledge on how the immune system interacts with pathogens means that there is increased understanding of the role of adjuvants and how the formulation of modern vaccines can be better tailored towards the desired clinical benefit. Continuing safety evaluation of licensed vaccines containing adjuvants/adjuvant systems suggests that their individual benefit-risk profile remains favorable. Adjuvants contribute to the initiation of the innate immune response induced by antigens; exemplified by inflammatory responses at the injection site, with mostly localized and short-lived effects. Activated effectors (such as APCs) then move to draining lymph nodes where they direct the type, magnitude and quality of the adaptive immune response. Thus, the right match of antigens and adjuvants can potentiate downstream adaptive immune responses, enabling the development of new efficacious vaccines. Many infectious diseases of worldwide significance are not currently preventable by vaccination. Adjuvants are the most advanced new technology in the search for new vaccines against challenging pathogens and for vulnerable populations that respond poorly to traditional vaccines.

In vitro replication phenotype of a novel (-1G) hepatitis B virus variant associated with HIV co-infection

The -1G mutant HBV is more prevalent in individuals co-infected with HIV/HBV than in individuals infected with HBV alone and in some cases is the dominant virus in circulation. This mutant is created by the deletion of a dGMP (-1G) from the guanine rich homopolymer sequence located at nts 2,085-2,090 (numbering from EcoRI site as position 1) in the HBV core gene. This deletion causes a frameshift generating a premature stop codon at (64) Asn in the HBV core gene (codon 93 in the precore gene), that truncates the precore protein, precursor of the secreted hepatitis B "e" antigen (HBeAg), and the core protein which forms the viral nucleocapsid. However, the replication phenotype of the -1G mutant HBV is unknown. An in vitro cell culture model in which hepatoma cells were transiently transfected with infectious cDNAs was used to show that the -1G mutant HBV is incapable of autonomous replication and, as expected, replication was restored to wild-type (wt) levels by supplying HBV core protein in trans. Although the -1G mutation had no deleterious effect on intracellular HBV-DNA levels, high levels of -1G mutant HBV relative to wt HBV reduced virus secretion and HBeAg secretion relative to empty vector controls. Importantly, the -1G mutant HBV also caused intracellular retention of truncated precore protein in the endoplasmic reticulum (ER) and Golgi apparatus. Together, these effects may be contributing to the increased pathology observed in the setting of HIV/HBV co-infection.

Hepatic TLR2 & TLR4 expression correlates with hepatic inflammation and TNF-α in HCV & HCV/HIV infection

Signalling activated by Toll-like receptors (TLRs) can result in the production of tumour necrosis factor alpha (TNF-α) which is implicated in hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infection. No study has examined or compared hepatic expression of TLRs in both HCV and HCV/HIV. Liver and peripheral blood mononuclear cells (PBMCs) were obtained from HCV & HCV/HIV-infected patients and PBMCs from HIV-infected patients. Liver RNA was analysed by microarray and reverse transcription quantitative PCR (RT-qPCR). PBMCs were analysed by flow cytometry. Associations with hepatic histology and infection type were sought. Forty-six HCV, 20 HIV and 27 HCV/HIV-infected patients were recruited. Increasing Metavir inflammatory activity score was associated with increased hepatic TLR mRNA by RT-qPCR: TLR2 (P ≤ 0.001), TLR4 (P = 0.008) and TNF-α (P ≤ 0.001). A high degree of correlation was seen between hepatic mRNA expression of TNF-αvs TLR2 (r(2) = 0.66, P < 0.0001) and TLR4 (r(2) = 0.60, P < 0.0001). No differences in TLR gene or protein expression was observed between HCV, HCV/HIV- or HIV-infected groups. Hepatic TLR2, TLR4 and TNF-α mRNA are associated with hepatic inflammation in both HCV and HCV/HIV infection. High correlation between TNF-α and TLR2/TLR4 suggests a role for the innate immune response in TNF-α production. Activation of the innate immune response appears to be independent of infection type.

Characterization of the innate immune signalling pathways in hepatocyte cell lines

Hepatitis B virus (HBV) infection is a major cause of liver-related morbidity and mortality. Toll-like receptors (TLRs) have recently been recognized to play an important role in the pathogenesis of chronic hepatitis B (CH-B). Furthermore, manipulation of TLR signalling pathways shows potential as an antiviral therapeutic strategy. Whether hepatocytes themselves possess intact TLR signalling pathways remains controversial. It is critical that cell culture models be developed to allow investigation of the interaction between HBV and the TLR signalling pathways. We have screened three hepatocyte cell lines for the integrity of pro-inflammatory responses and antiviral cytokines following stimulation with interleukin-1 (IL-1) and different TLR ligands. We observed that Huh-7, HepG2 and PH5CH8 cells selectively responded to IL-1 and TLR2 ligands, leading to the activation of NF-kappaB. In addition, the PH5CH8 cell lines were able to induce type 1 interferon (IFN) via both TLR3 and RIG-I following stimulation with poly I:C, HepG2 cells mounted an IFN response via RIG-I only, whereas Huh-7 cells were unresponsive. We conclude that the hepatocyte cell lines investigated display a repertoire of TLR signalling, albeit limited, suggesting that hepatocytes may themselves play an active role in innate immune responses to viruses such as HBV. Furthermore, particular hepatoma cell lines are suitable for investigating the interaction between HBV and hepatocyte-expressed pattern recognition receptors.

Tooth brushing habits in uninstructed adults--frequency, technique, duration and force

Professional recommendations for individual oral hygiene mostly include tooth brushing at least twice daily for 2-3 min with gentle force using the Bass technique or modifications of it. This study evaluated whether habitual tooth brushing actually meets these standards. Uninstructed adults (n = 103; mean age 31 +/- 6 years; 61 female, 42 male) with habitual manual tooth brushing were given a self-administered questionnaire about the frequency of brushing and a computer system recorded their brushing technique, duration and force. The majority (79.6%) of participants brushed twice daily. The mean brushing duration was 96.6 +/- 36.0 s, the mean brushing force was 2.3 +/- 0.7 N (max. 4.1 N), and no significant differences were found for quadrants. Most subjects (73.8%) brushed with circling, 8.7% with horizontal/scrubbing, 13.6% with horizontal/circling and 3.9% with vertical/sweeping movements. Modified Bass technique was not observed. When appropriate brushing habits were defined as brushing at least twice daily for 120 s with a brushing force of less than 3 N and with circling or vertical sweeping movements, only 25.2% of the participants fulfilled all criteria, emphasising the ongoing need for oral hygiene education.

Defective hepatitis B virus DNA is not associated with disease status but is reduced by polymerase mutations associated with drug resistance

Defective hepatitis B virus DNA (dDNA) is reverse-transcribed from spliced hepatitis B virus (HBV) pregenomic messenger RNA (pgRNA) and has been identified in patients with chronic HBV (CH-B). The major 2.2-kb spliced pgRNA encodes a novel HBV gene product, the hepatitis B splice protein (HBSP) via a deletion and frame shift within the polymerase. Although spliced RNA and HBSP expression have been associated with increased HBV DNA levels and liver fibrosis, the role of dDNA in HBV-associated disease is largely undefined. Our aims were to (1) compare the relative proportions of dDNA (% dDNA) in a range of HBV-infected serum samples, including patients with human immunodeficiency virus (HIV)/HBV coinfection and HBV-monoinfected persons with differing severities of liver disease, and (2) determine the effect of mutations associated with drug resistance on defective DNA production. Defective DNA was detected in 90% of persons with CH-B. There was no significant difference in the relative abundance of dDNA between the monoinfected and HIV/HBV-coinfected groups. We also found no association between the % dDNA and alanine aminotransferase, hepatitis B e antigen status, HBV DNA levels, fibrosis levels, compensated or decompensated liver cirrhosis, genotype, or drug treatment. However, the % dDNA was significantly lower in individuals infected with lamivudine-resistant (LMV-R) HBV compared with wild-type HBV (P < 0.0001), indicating that antiviral drug resistance alters the balance between defective and genomic length DNA in circulation. Experiments in vitro using HBV encoding LMV-R mutations confirmed these results.

CONCLUSION

Our results identified no association between dDNA and parameters associated with disease status and suggested that the relative abundance of dDNA is largely dependent on the integrity of the HBV polymerase and is unrelated to the severity of liver disease.

Suprakondyl�re Extension einer pertrochant�ren Femurfraktur bei einem Patienten mit Unterschenkelamputation

Pertrochanteric femur fracture is rare in patients with lower leg amputation. Using supracondylar traction takes full advantage of the extension table. Intraoperative insertion of a Steinmann pin for traction is a well-known low-risk procedure. In our opinion, this kind of extension is a simple procedure that carries no risks for postoperative prosthetic management in patients with lower leg amputation.

A SOX9 defect of calmodulin-dependent nuclear import in campomelic dysplasia/autosomal sex reversal

During mammalian sex determination, SOX9 is translocated into the nuclei of Sertoli cells within the developing XY gonad. The N-terminal nuclear localization signal (NLS) is contained within a SOX consensus calmodulin (CaM) binding region, thereby implicating CaM in nuclear import of SOX9. By fluorescence spectroscopy and glutaraldehyde cross-linking, we show that the SOX9 HMG domain and CaM interact in vitro. The formation of a SOX9.CaM binary complex is calcium-dependent and is accompanied by a conformational change in SOX9. A CaM antagonist, calmidazolium chloride (CDZ), was observed to block CaM recognition of SOX9 in vitro and inhibit both nuclear import and consequent transcriptional activity of SOX9 in treated cells. The significance of the SOX9-CaM interaction was highlighted by analysis of a missense SOX9 mutation, A158T, identified from a XY female with campomelic dysplasia/autosomal sex reversal (CD/SRA). This mutant binds importin beta normally despite defective nuclear import. Fluorescence and quenching studies indicate that in the unbound state, the A158T mutant shows a similar conformation to that of the WT SOX9, but in the presence of CaM, the mutant undergoes unusual conformational changes. Furthermore, SOX9-mediated transcriptional activation by cells expressing the A158T mutant is more sensitive to CDZ than cells expressing WT SOX9. These results suggest first that CaM is involved in the nuclear transport of SOX9 in a process likely to involve direct interaction and second, that CD/SRA can arise, at least in part, from a defect in CaM recognition, ultimately leading to reduced ability of SOX9 to activate transcription of cartilage and testes-forming genes.

Decreased neurotropism of nef long terminal repeat (nef/LTR)-deleted simian immunodeficiency virus

Simian immunodeficiency virus (SIV) infection of macaques results in neurological abnormalities similar to those of human immunodeficiency virus (HIV)-associated dementia in humans and is a valuable system for the identification of viral neurotropic and neurovirulence factors. The authors recently established an SIV-macaque model where macaques can be infected with wild-type or nef/LTR-deleted SIVmac239 via administration of purified proviral DNA. In this study, the ability of wild-type and nef/LTR-deleted SIV infections to enter the cerebral spinal fluid (CSF) and brain was analyzed. In situ polymerase chain reaction (PCR) readily detected SIV gag DNA-positive cells in the mid-frontal gyrus and basal ganglia of the wild-type SIV-infected macaques, but not in nef/LTR-deleted SIV-infected or SIV-uninfected macaques. PCR on extracted DNA confirmed the in situ results, with multiple brain regions of the wild-type SIV-infected macaques positive for both gag and wild-type nef, whereas in the nef/LTR-deleted SIV-infected macaques, nef/LTR and gag DNA were undetectable. Further, macaques infected with nef/LTR-deleted SIV, which later became superinfected with wild-type SIV, also remained negative for SIV DNA in the brain by both in situ and extracted DNA techniques, despite having high levels of SIV RNA both in the CSF and plasma. This study provides evidence of the inability of nef/LTR-deleted SIV to initiate central nervous system (CNS) infection and suggests that, in the brain regions examined, nef/LTR-deleted viruses have either diminished neurotropism or insufficient systemic viral replication for entry into the CNS.

Evidence of recombination between 3' and 5' LTRs in macaques inoculated with SIV DNA

Proviral SIV DNA inoculation of macaques is an efficient method to initiate wild-type and attenuated SIV infections. However, we found that macaques inoculated with SIV DNA engineered to contain a single 105-bp deletion in the 3' nef/LTR overlap region had SIV sequences subsequently isolated that had partially or fully repaired the deletion with wild-type sequence. Animals inoculated with SIV DNA containing identical deletions in both the 5' and 3' LTRs did not repair the deletion. Recombination events occurred early, most likely by homologous recombination with sequences from the wild-type 5' LTR. This sequence analysis is the first demonstration of homologous recombination in vivo following administration of a single SIV strain.

Generation of tumor-associated cytotoxic T lymphocytes requires interleukin 4 from CD8(+) T cells

Activation of tumor-associated CD8(+) cytotoxic T lymphocytes (CTLs) often requires antigen representation, e.g., by dendritic cells (DCs), and CD4(+) T cell help. Previously, we showed that CTL-mediated tumor immunity required interleukin 4 (IL-4) during the immunization but not effector phase. To determine the source and target cells of IL-4, we performed adoptive T cell transfers using CD4(+) and CD8(+) T cells from IL-4(-/-) and IL-4R(-/-) mice and analyzed CTL generation. Even though necessary for CTL generation, CD4(+) T cells did not need to express IL-4 or IL-4R. Surprisingly, CTL generation required IL-4 but not IL-4R expression by CD8(+) T cells. As IL-4 (a) was expressed by naive CD8(+) T cells within 24 h after antigen encounter, (b) IL-4 induced DC maturation, and (c) CTL development was impaired in T cell-reconstituted IL-4R(-/-) mice, CD8(+) T cell-derived IL-4 appears to act on DCs. We conclude that CD4(+) and CD8(+) T cells provide different signals for DC activation during CTL generation.

Tumor rejection by disturbing tumor stroma cell interactions

The stroma of solid tumors is a complex network of different cell types. We analyzed stroma cell interactions in two tumor models during cyclophosphamide (Cy)-induced tumor rejection. In growing tumors, tumor infiltrating macrophages (TIMs) produced interleukin (IL)-10. Beginning 6 h after Cy-treatment T cells in the tumor were inactivated and TIMs switched to interferon (IFN)-gamma production. Both, IL-10 production before and IFN-gamma production after Cy-treatment by TIMs required T cells. With the same kinetics as TIMs started to produce IFN-gamma the tumor vasculature was destroyed which required IFN-gamma receptor expression on host but not tumor cells. These events preceded hemorrhagic necrosis and residual tumor cell elimination by T cells. Together, T cells regulate the function of TIMs and tumor rejection can be induced by disturbing the stroma network.

Vaccination with attenuated simian immunodeficiency virus by DNA inoculation

Delivering attenuated lentivirus vaccines as proviral DNA would be simple and inexpensive. Inoculation of macaques with wild-type simian immunodeficiency virus strain mac239 (SIV(mac239)) DNA or SIV(mac239) DNA containing a single deletion in the 3' nef-long terminal repeat overlap region (nef/LTR) led to sustained SIV infections and AIDS. Injection of SIV(mac239) DNA containing identical deletions in both the 5' LTR and 3' nef/LTR resulted in attenuated SIV infections and substantial protection against subsequent mucosal SIV(mac251) challenge.

Rapid, ATP-dependent degradation of a truncated D1 protein in the chloroplast

The D1 protein constitutes one of the reaction center subunits of photosystem II and turns over rapidly due to photooxidative damage. Here, we studied the degradation of a truncated D1 protein. A plasmid with a precise deletion in the reading frame of the psbA gene encoding D1 was introduced into the chloroplast of Chlamydomonas reinhardtii. A homoplasmic mutant containing the desired gene was able to synthesize the truncated form of the polypeptide, but could not accumulate significant levels of it. As a consequence, other central photosystem II subunits did not assemble within the thylakoid membrane. In vivo pulse-chase experiments showed that the abnormal D1 protein is rapidly degraded in the light. Degradation was delayed in the light in the presence of an uncoupler, or when cells were incubated in the dark. Pulse-chase experiments performed in vitro indicate that an ATP and metal-dependent protease is responsible for the breakdown process. The paper describes the first in vivo and in vitro functional test for ATP-dependent degradation of a defect polypeptide in chloroplasts. The possible involvement of proteases similar to those removing abnormal proteins in prokaryotic organisms is discussed on the basis of proteases recently identified in chloroplasts.

Compound effects of point mutations causing campomelic dysplasia/autosomal sex reversal upon SOX9 structure, nuclear transport, DNA binding, and transcriptional activation

Human mutations in the transcription factor SOX9 cause campomelic dysplasia/autosomal sex reversal. Here we identify and characterize two novel heterozygous mutations, F154L and A158T, that substitute conserved "hydrophobic core" amino acids of the high mobility group domain at positions thought to stabilize SOX9 conformation. Circular dichroism studies indicated that both mutations disrupt alpha-helicity within their high mobility group domain, whereas tertiary structure is essentially maintained as judged by fluorescence spectroscopy. In cultured cells, strictly nuclear localization was observed for wild type SOX9 and the F154L mutant; however, the A158T mutant showed a 2-fold reduction in nuclear import efficiency. Importin-beta was demonstrated to be the nuclear transport receptor recognized by SOX9, with both mutant proteins binding importin-beta with wild type affinity. Whereas DNA bending was unaffected, DNA binding was drastically reduced in both mutants (to 5% of wild type activity in F154L, 17% in A158T). Despite this large effect, transcriptional activation in cultured cells was only reduced to 26% in F154L and 62% in A158T of wild type activity, suggesting that a small loss of SOX9 transactivation activity could be sufficient to disrupt proper regulation of target genes during bone and testis formation. Thus, clinically relevant mutations of SOX9 affect protein structure leading to compound effects of reduced nuclear import and reduced DNA binding, the net effect being loss of transcriptional activation.

The sequence requirements for a functional Escherichia coli replication origin are different for the chromosome and a minichromosome

We have developed a simple three-step method for transferring oriC mutations from plasmids to the Escherichia coli chromosome. Ten oriC mutations were used to replace the wild-type chromosomal origin of a recBCsbcB host by recombination. The mutations were subsequently transferred to a wild-type host by transduction. oriC mutants with a mutated DnaA box R1 were not obtained, suggesting that R1 is essential for chromosomal origin function. The other mutant strains showed the same growth rates, DNA contents and cell mass as wild-type cells. Mutations in the left half of oriC, in DnaA boxes M, R2 or R3 or in the Fis or IHF binding sites caused moderate asynchrony of the initiation of chromosome replication, as measured by flow cytometry. In mutants with a scrambled DnaA box R4 or with a modified distance between DnaA boxes R3 and R4, initiations were severely asynchronous. Except for oriC14 and oriC21, mutated oriCs could not, or could only poorly, support minichromosome replication, whereas most of them supported chromosome replication, showing that the classical definition of a minimal oriC is not valid for chromosome replication. We present evidence that the functionality of certain mutated oriCs is far better on the chromosome than on a minichromosome.

Age-dependent changes in magnetization transfer contrast of white matter in the pediatric brain

BACKGROUND AND PURPOSE

It is unknown to what extent magnetization transfer contrast (MTC) in white matter of the brain changes during myelination. The goal of this study was to measure the age-dependent changes of MTC in different regions of the pediatric brain and to evaluate their relation to T2 relaxation times.

METHODS

Seventy children aged 1 week to 80 months without evidence of organic brain disease underwent MR imaging of the brain. A double-echo spin-echo (SE) sequence and an SE sequence with and without an off-resonance pulse were performed in the axial orientation. Using paired images, we calculated MTC ratios in 13 predefined regions of the brain and compared them with the T2 relaxation times measured in the same areas. Regression analysis was performed for both parameters to evaluate age dependency.

RESULTS

MTC in white matter increased during myelination from a range of 13% to 19% to a range of 34% to 37%. At the same time, T2 relaxation times decreased from a range of 115 to 160 milliseconds to a range of 60 to 70 milliseconds after myelination. For both MTC and T2 relaxation times, age dependency could be expressed by a monoexponential function.

CONCLUSION

A strong positive correlation exists between MTC ratios and the degree of myelination in the pediatric brain, and an inverse correlation exists between MTC and T2 relaxation times. Fast proton relaxation within macromolecules in the myelinated white matter and subsequent MT may be the most important reason for the decreasing T2 relaxation time of white matter during brain myelination.

An aquaporin-like gene required for the Brassica self-incompatibility response

Self-incompatibility in Brassica refers to the rejection of self-related pollen and is mediated by a receptor protein kinase localized to the plasma membrane of the stigma epidermis in the flower. The recessive mutation mod eliminates self-incompatibility in the stigma. In mod mutants, self-compatibility was shown to be associated with the absence of transcripts encoded by an aquaporin-related gene. This observation suggests that a water channel is required for the self-incompatibility response of Brassica, which is consistent with the concept that regulation of water transfer from the stigma to pollen is a checkpoint in the early events of pollination in the crucifer family.

Comminuted humeral head fractures: a multicenter analysis

Three centers' experience with 93 comminuted humeral head fractures were clinically (Constant score) and radiologically (Neer) analyzed. The results revealed fundamental differences between the various types of fractures depending on the number of fragments. For three-part fractures open reduction and internal fixation (mean Constant scores 83 and 91 points, respectively) or conservative treatment (78 points) seem to be indicated. The prognosis for four-part fractures is determined largely by the vascular supply of the head fragment with a high risk of humeral head osteonecrosis. For this reason primary prosthetic replacement (mean Constant score, 74 points compared with 54 points for conservative treatment and 52 points for open reduction) should be recommended for this type of fracture. In conclusion, we stress the importance of fracture type directing the therapeutic modality.

Light-induced biogenesis of the light-harvesting complexes of Photosystems I and II : Gene expression and protein accumulation

The light-harvesting complexes of Photosystems I and II contain multiple chlorophyll-carotenoid-binding proteins. The stoichiometry and topology of the LHCs is precisely defined to optimally funnel captured light energy to the reaction center. The manner in which this exact arrangement is accomplished is not known. As an initial means to understand the mechanisms involved in establishing a functional LHC, the influence of light on LHC gene expression and protein accumulation was studied during the light-induced greening of etiolated wild type and chlorophyll b-less mutant barley seedlings. Light, involving phytochrome, promotes the expression of all LHC genes with the same relative kinetics. LHC protein accumulation closely parallels the increases observed in transcript levels. Differential accumulation of LHC transcripts or protein was not evident in wild type seedlings. Post-translational factors are likely to be involved in fine tuning the position and stoichiometry of the individual LHCs around the reaction center.

Stability of the Apoproteins of Light-Harvesting Complex I and II during Biogenesis of Thylakoids in the Chlorophyll b-less Barley Mutant Chlorina f2

Transcription and translation of Lhc (cab) genes have been compared in the chlorina f2 mutant of barley (Hordeum vulgare) and its wild type to study the effect of chlorophyll b's absence on the regulation of assembly of the light-harvesting complexes (LHC). All tested genes were transcribed and the amount of their respective mRNAs increased rhythmically upon illumination of etiolated mutant plants. The synthesis of individual LHC apoproteins also had a rhythmic pattern when total leaf protein extracts were examined, whereas they increased gradually in the thylakoid. Only some LHC pigment-proteins present in wild-type thylakoids were found in mature mutant membranes. Thus, only the 25-kD (type 3) apoprotein of the three apoproteins of the major LHC IIb complex survived. The amount of the minor LHC II pigment-proteins was considerably reduced but not to zero. Photosystem I had some of the two LHC la apoproteins but had little of those of LHC lb. This was reflected in a shift of the 77-K emission maximum of whole leaves from 741 to 732 nm. It is concluded that the two largest LHC IIb and the LHC Ib apoproteins need chlorophyll b for stable integration into the membrane and that posttranslational regulation plays a major role in LHC assembly.