Timing of radiotherapy (RT) after radical prostatectomy (RP): long-term outcomes in the RADICALS-RT trial (NCT00541047).

BACKGROUND: The optimal timing of radiotherapy (RT) after radical prostatectomy for prostate cancer has been uncertain. RADICALS-RT compared efficacy and safety of adjuvant RT versus an observation policy with salvage RT for prostate-specific antigen (PSA) failure. PATIENTS AND METHODS: RADICALS-RT was a randomised controlled trial enrolling patients with ≥1 risk factor (pT3/4, Gleason 7-10, positive margins, preoperative PSA≥10 ng/ml) for recurrence after radical prostatectomy. Patients were randomised 1:1 to adjuvant RT ('Adjuvant-RT') or an observation policy with salvage RT for PSA failure ('Salvage-RT') defined as PSA≥0.1 ng/ml or three consecutive rises. Stratification factors were Gleason score, margin status, planned RT schedule (52.5 Gy/20 fractions or 66 Gy/33 fractions) and treatment centre. The primary outcome measure was freedom-from-distant-metastasis (FFDM), designed with 80% power to detect an improvement from 90% with Salvage-RT (control) to 95% at 10 years with Adjuvant-RT. Secondary outcome measures were biochemical progression-free survival, freedom from non-protocol hormone therapy, safety and patient-reported outcomes. Standard survival analysis methods were used; hazard ratio (HR)<1 favours Adjuvant-RT. RESULTS: Between October 2007 and December 2016, 1396 participants from UK, Denmark, Canada and Ireland were randomised: 699 Salvage-RT, 697 Adjuvant-RT. Allocated groups were balanced with a median age of 65 years. Ninety-three percent (649/697) Adjuvant-RT reported RT within 6 months after randomisation; 39% (270/699) Salvage-RT reported RT during follow-up. Median follow-up was 7.8 years. With 80 distant metastasis events, 10-year FFDM was 93% for Adjuvant-RT and 90% for Salvage-RT: HR=0.68 [95% confidence interval (CI) 0.43-1.07, P=0.095]. Of 109 deaths, 17 were due to prostate cancer. Overall survival was not improved (HR=0.980, 95% CI 0.667-1.440, P=0.917). Adjuvant-RT reported worse urinary and faecal incontinence 1 year after randomisation (P=0.001); faecal incontinence remained significant after 10 years (P=0.017). CONCLUSION: Long-term results from RADICALS-RT confirm adjuvant RT after radical prostatectomy increases the risk of urinary and bowel morbidity, but does not meaningfully improve disease control. An observation policy with salvage RT for PSA failure should be the current standard after radical prostatectomy. TRIAL IDENTIFICATION: RADICALS, RADICALS-RT, ISRCTN40814031, NCT00541047.

Dimorphism in cryptophytes-The case of Teleaulax amphioxeia/Plagioselmis prolonga and its ecological implications.

Growing evidence suggests that sexual reproduction might be common in unicellular organisms, but observations are sparse. Limited knowledge of sexual reproduction constrains understanding of protist ecology. Although Teleaulax amphioxeia and Plagioselmis prolonga are common marine cryptophytes worldwide, and are also important plastid donors for some kleptoplastic ciliates and dinoflagellates, the ecology and development of these protists are poorly known. We demonstrate that P. prolonga is the haploid form of the diploid T. amphioxeia and describe the seasonal dynamics of these two life stages. The diploid T. amphioxeia dominates during periods of high dissolved inorganic nitrogen (DIN) and low irradiance, temperature, and grazing (winter and early spring), whereas the haploid P. prolonga becomes more abundant during the summer, when DIN is low and irradiance, temperature, and grazing are high. Dimorphic sexual life cycles might explain the success of this species by fostering high genetic diversity and enabling endurance in adverse conditions.

Surgeons' posture and muscle strain during laparoscopic and robotic surgery.

BACKGROUND: It is assumed that conventional laparoscopy (LAP) and robotic-assisted laparoscopic surgery (RALS) differ in terms of the surgeon's comfort. This study compared muscle workload, work posture and perceived physical exertion of surgeons performing LAP or RALS. METHODS: Colorectal surgeons with experience in advanced LAP and RALS performed one of each operation. Bipolar surface electromyography (EMG) recordings were made from forearm, shoulder and neck muscles, and expressed relative to EMG maximum (%EMGmax ). The static, median and peak levels of muscle activity were calculated, and an exposure variation analysis undertaken. Postural observations were carried out every 10 min, and ratings of perceived physical exertion before and after surgery were recorded. RESULTS: The study included 13 surgeons. Surgeons performing LAP showed higher static, median, and peak forearm muscle activity than those undertaking RALS. Muscle activity at peak level was higher during RALS than LAP. Exposure variation analysis demonstrated long-lasting periods of low-level intensity muscle activity in the shoulders for LAP, in the forearms for RALS, and in the neck for both procedures. Postural observations revealed a greater need for a change in work posture when performing LAP compared with RALS. Perceived physical exertion was no different between the surgical modalities. CONCLUSION: Minimally invasive surgery requires long-term static muscle activity with a high physical workload for surgeons. RALS is less demanding on posture.

ANTECEDENTES: Se asume que la cirugía laparoscópica (laparoscopic, LAP) y la cirugía laparoscópica asistida por robot (robotic-assisted laparoscopic surgery, RALS) difieren en cuanto a la comodidad del cirujano. En este estudio se comparó la carga de trabajo muscular, la postura de trabajo y el esfuerzo físico percibido por los cirujanos al realizar LAP o RALS. MÉTODOS: Trece cirujanos colorrectales con experiencia en LAP avanzada y RALS realizaron una operación con cada uno de los abordajes. Se registró la electromiografía de superficie bipolar en los músculos del antebrazo, del hombro y del cuello, y se expresó en relación con el EMG máximo (% EMGmax). Se calculó el nivel de actividad muscular estático, mediano y pico, y se realizó un análisis de variación de la exposición. Las observaciones posturales se llevaron a cabo cada diez minutos y se registraron las valoraciones del esfuerzo físico percibido antes y después de la cirugía. RESULTADOS: La práctica de LAP mostró una mayor actividad muscular estática, mediana y pico del antebrazo en comparación con la práctica de RALS. El hombro izquierdo mostró la mayor actividad muscular en RALS a nivel máximo. El análisis de variación de exposición demostró periodos prolongados de actividad muscular de baja intensidad para LAP en los hombros, para RALS en los antebrazos y para ambos en el cuello. Las observaciones posturales mostraron una mayor necesidad de un cambio en la postura de trabajo al realizar LAP en comparación con RALS. El esfuerzo físico percibido no fue diferente entre ambas modalidades quirúrgicas. CONCLUSIÓN: La cirugía mínimamente invasiva requiere una actividad muscular estática prolongada con una alta carga de trabajo físico para los cirujanos. RALS es menos exigente en el aspecto postural.

Swimming behavior and prey retention of the polychaete larvae Polydora ciliata (Johnston).

The behavior of the ubiquitous estuarine planktotrophic spionid polychaete larvae Polydora ciliata was studied. We describe ontogenetic changes in morphology, swimming speed and feeding rates and have developed a simple swimming model using low Reynolds number hydrodynamics. In the model we assumed that the ciliary swimming apparatus is primarily composed of the prototroch and secondarily by the telotroch. The model predicted swimming speeds and feeding rates that corresponded well with the measured speeds and rates. Applying empirical data to the model, we were able to explain the profound decrease in specific feeding rates and the observed increase in the difference between upward and downward swimming speeds with larval size. We estimated a critical larval length above which the buoyancy-corrected weight of the larva exceeds the propulsion force generated by the ciliary swimming apparatus and thus forces the larva to the bottom. This modeled critical larval length corresponded to approximately 1 mm, at which, according to the literature, competence for metamorphosis and no more length increase is observed. These findings may have general implications for all planktivorous polychaete larvae that feed without trailing threads. We observed bell shaped particle retention spectra with a minimum prey size of approximately 4 microm equivalent spherical diameter, and we found that an ontogenetic increase in maximum prey size add to a reduction in intra-specific food competition in the various larval stages. In a grazing experiment using natural seawater, ciliates were cleared approximately 50% more efficiently than similar sized dinoflagellates. The prey sizes retainable for P. ciliata larvae covers the microplankton fraction and includes non-motile as well as motile prey items, which is why the larvae are trophically positioned among the copepods and dinoflagellates. Not only do larval morphology and behavior govern larval feeding, prey behavior also influences the feeding efficiency of Polydora ciliata.

OTC use of a topical nasal spray solution containing xylometazoline plus ipratropium in patients with common cold.

BACKGROUND: Combination of xylometazoline and ipratropium in a nasal spray provides fast, effective symptomatic relief of nasal congestion and rhinorrhea in adults with common cold. OBJECTIVES: To gather data in a non-prescription setting regarding the safety, pattern of use, patients' general assessment of treatment and suitability of making available without medical prescription of this topical combination nasal spray. DESIGN: Post-marketing, non-interventional, non-controlled study reflecting normal over-the-counter (OTC) use of the spray in adults with common cold (n = 1,019). Main outcome measures included pattern of use (patient-reported effectiveness, compliance with treatment) and safety (adverse drug reaction (ADR) reports). RESULTS: Over 92% of patients used the product for the intended indication, 81.4% used it 2 - 3 times/day and the median duration of treatment was 6 days. In total, 39.7% of patients reported 585 ADRs (mean 1.45 ADR/patient) while 60.3% reported no ADRs. Most common side effects were nasal dryness (12.4%), blood tinged mucus (9.3%), nasal discomfort (6.2%), epistaxis (4.2%), generally harmless and of mild severity. Patients who used the product outside the approved indication did not seem to have a higher risk of ADRs. Mean general impression score was 3.4, with 79% of patients rating treatment as "good" to "excellent". CONCLUSIONS: The topical combination nasal spray (xylometazoline plus ipratropium) for the symptomatic relief of nasal congestion and rhinorrhea in adults with common cold has a good safety profile and results in high patient satisfaction in an OTC setting. No reasons could be found to oppose the assertion that the combination spray is suitable for classification as a product not subject to medical prescription.

A clinical evaluation of endoscopically placed self-expanding metallic stents in patients with acute large bowel obstruction.

BACKGROUND AND AIMS: Self-expanding metallic stents (SEMS) have since 1991 established themselves as an option in the treatment of large bowel obstruction. The aim of this study was to evaluate the use of SEMS in management of acute colorectal obstructions at a Danish Surgical Gastroenterology center. MATERIAL AND METHODS: Retrospective review of charts from all patients who, in the period Marts 2002 to December 2007 underwent insertion of a SEMS for an acute large bowel obstruction. RESULTS: Of 45 patients included, SEMS was intended as a bridge to surgery in 20 patients and as palliation in 25 patients. For malignant etiology, the SEMS procedure was a technical and clinical success in 97.4% of the cases. Complications occurred in 21%, mortality rate 2,6%. For benign etiology, the SEMS procedure was a technical success in 85.7%, and a clinical success in 71.4%. Complications occurred in 71.4% of the benign cases with a mortality rate of 28,6%. CONCLUSIONS: Placement of SEMS for acute large bowel obstruction with malignant etiology is an effective and safe procedure with low mortality and morbidity. However results for benign obstructions are questionable and more research is needed to determine the role of SEMS.

Reducing added sugar intake in Norway by replacing sugar sweetened beverages with beverages containing intense sweeteners - a risk benefit assessment.

A risk benefit assessment in Norway on the intake of added sugar, intense sweeteners and benzoic acid from beverages, and the influence of changing from sugar sweetened to diet beverages was performed. National dietary surveys were used in the exposure assessment, and the content of added sugar and food additives were calculated based on actual contents used in beverages and sales volumes provided by the manufactures. The daily intake of sugar, intense sweeteners and benzoic acid were estimated for children (1- to 13-years-old) and adults according to the current intake level and a substitution scenario where it was assumed that all consumed beverages contained intense sweeteners. The change from sugar sweetened to diet beverages reduced the total intake of added sugar for all age groups but especially for adolescent. This change did not result in intake of intense sweeteners from beverages above the respective ADIs. However, the intake of acesulfame K approached ADI for small children and the total intake of benzoic acid was increased to above ADI for most age groups. The highest intake of benzoic acid was observed for 1- to 2-year-old children, and benzoic acid intake in Norwegian children is therefore considered to be of special concern.

Randomized clinical trial comparing radially expanding trocars with conventional cutting trocars for the effects on pain after laparoscopic cholecystectomy.

BACKGROUND: Trocar incisions are important sources of pain the first days after laparoscopic cholecystectomy. Radially expanding trocars may cause less pain than conventional cutting trocars. METHODS: In a patient- and observer-blinded trial, 80 patients were randomized to undergo laparoscopic cholecystectomy using either radially expanding trocars (radial group) or conventional cutting trocars (cutting group). Two 10-mm and two 5-mm trocars were used in both treatment groups. All the patients received standardized anesthetic and analgesic treatment. The primary outcome was incisional pain. Pain was registered during mobilization using a visual analog scale (VAS) and a verbal rating scale (VRS) before and 6 h after the operation, and at postoperative days 1 and 2. The needs for a fascial incision to retract the gallbladder, active surgical hemostasis, and supplementary requirements of opioids during the hospital stay were registered. In addition, 2 days after the operation, the incidence and severity of suggilations at the trocar incisions were measured. RESULTS: Data from 77 patients were available for statistical analysis. In the radial group, 23 patients needed fascial incision for gallbladder retraction compared with 11 patients in the cutting group (p = 0.006). No significant intergroup differences in VAS or VRS pain scores or any other variable were found. CONCLUSIONS: The use of radially expanding trocars has no effect on incisional pain after laparoscopic cholecystectomy.

Amyloidosis of the seminal vesicle--a case report and review of the literature.

The finding of amyloid deposits in the seminal vesicles has been known for many years. The deposits are usually localized and asymptomatic. In recent years seminal vesicle amyloidosis has been reported to simulate prostate and bladder cancer invasion on MRI. We therefore feel that knowledge of the entity is important and present herein a typical case confirming the previous findings that amyloidosis of the seminal vesicles is a unique form of amyloidosis, a relatively common incidental finding and one that may be related to prostate cancer.

Mucosal vaccination against encapsulated respiratory bacteria--new potentials for conjugate vaccines?

Polysaccharide (PS)-encapsulated bacteria such as Haemophilus influenzae type b (Hib), Streptococcus pneumoniae (pneumococcus), Neisseria meningitides (meningococcus) and group B streptococcus (GBS), cause a major proportion of disease in early childhood. Native PS vaccines are immunogenic and provide protection against disease in healthy adults but do not induce immunological memory. PSs are T-cell-independent antigens and do not elicit antibodies in infants and young children, but by conjugating PS to proteins they become T-cell dependent and immunogenic at an early age. Despite excellent efficacy of PS-protein conjugate vaccines against invasive disease, protection against mucosal infections such as pneumococcal otitis media has been less efficacious. Circulating PS-specific antibodies may protect against infections at mucosal sites, but mucosal immunoglobulin A antibodies may also contribute significantly to protection against mucosal infections. Mucosal immunization of experimental animals with conjugate vaccines against Hib, pneumococcus, meningococcus and GBS induces systemic and mucosal immune responses, which provide protection against carriage, otitis media and invasive disease in a variety of challenge models, providing new means for protection against encapsulated bacteria. In addition, mucosal immunization of neonatal mice with a pneumococcal conjugate and the nontoxic adjuvant LT-K63 has been superior to parenteral immunization in eliciting protective antibodies and PS-specific memory, and thus circumventing the limitations of antibody responses to PS that are responsible for enhanced susceptibility of neonates and infants to infections caused by encapsulated bacteria. Through T-cell dependent enhanced immunogenicity of PS-protein conjugate vaccines, mucosal immunization could be an attractive approach for early life immunization against encapsulated bacteria.

Nephropexy ad modum Albarran Marion: long-term follow-up.

OBJECTIVE: To report a long-term follow-up of nephropexy ad modum (a.m.) Albarran Marion. MATERIAL AND METHODS: Between 1980 and 1999, 18 women (mean age 42.6 years) underwent nephropexy a.m. Albarran Marion. The duration of symptoms varied from 7 months to 9 years. All patients were examined preoperatively using excretory urography and renography in both the supine and erect positions in order to document renal descent. Patients with decreased renal function also underwent postoperative renography. A questionnaire concerning pre- and post-treatment symptoms was sent to all patients. RESULTS: Hospitalization averaged 7.2 days (range 4-15 days). Pneumothorax occurred in 7 patients, 3 of whom required temporary drainage. One patient developed pneumonia and another a retroperitoneal haematoma; no other complications occurred. All postoperative renography findings were normal. Median follow-up time was 11.2 years (range 2-21 years). At follow-up, 87.5% of patients were satisfied with the results and were free from pain. Two patients were not satisfied with the results; retrospectively the indications for surgery in these 2 cases were not absolute. CONCLUSIONS: Operative treatment for symptomatic nephroptosis should only be performed in selected cases. We present a success rate of 87.5% for nephropexy a.m. Albarran Marion, at a mean follow-up of 11.2 years, which equals the best results obtained with other procedures. The choice of operative procedure for symptomatic nephroptosis must be based on the special interests and skills available at the institutions concerned.

Urinary bladder volume measurements: comparison of three ultrasound calculation methods.

OBJECTIVE: To assess the precision of three different automatic calculation methods in real-time bladder volume measurement. MATERIAL AND METHODS: Bladders from 34 medical staff volunteers were examined. Two examinations of each subject were performed independently by 2 examiners using 2 identical ultrasound scanners with no delay between the examinations. Three different automatic calculation algorithms, available as software in the ultrasound scanner, were applied on the frozen ultrasound pictures. After registration of the voided volume with an uroflowmeter, the subjects were scanned again in order to assure complete emptying. RESULTS: Voided volumes ranged from 45 ml to 508 ml. The precision of each method was equal but the LWH method measured significantly lower values than the ELLIPSOID and AREA method. Errors in the range of -56.1% to +58.8% for all volumes and methods were found. Data for voided volumes greater than 150 ml (n = 29) were investigated separately, but no significant improvement in accuracy for any of the methods was found. CONCLUSIONS: Ultrasound bladder volume calculation is an easy method for estimation of bladder volume. The prolate ellipsoid method (LWH) is recommended as the standard calculation method because it is fast and easy. Unacceptable large measure errors are found and too rigid conclusions based on ultrasound measurements of bladder volume should be avoided.

A 4-mm probe for (13)C CP/MAS NMR of solids at 21.15 T.

The design of a broadband 4-mm magic-angle spinning (MAS) X-(1)H/(19)F double resonance probe for cross-polarization (CP)/MAS NMR studies at 21.15 T ((1)H at 900 MHz) is described. The high-frequency (1)H/(19)F channel employs a new and efficient transmission line tuning design. The first (13)C CP/MAS NMR spectra recorded at 21.15 T have been obtained with this probe and exhibit the best S/N per milligram sample of hexamethylbenzene achieved so far for a 4-mm rotor.

New opportunities for high-resolution solid-state NMR spectroscopy of oxide materials at 21.1- and 18.8-T fields.

We present here high-resolution solid state NMR spectra of several oxide and silicate materials that illustrate the improvements obtainable with very high external fields (18.8 and 21.1 T), with probes capable of tuning to a wide frequency range that allow observations of nuclides from high to low magnetogyric ratio. We discuss 27Al MAS spectra for the zeolite scolecite (CaAl2Si3O10 x 3H2O), 17O MAS data for analcime (NaAlSi2O6 x H2O), calcium monoaluminate (CaAI2O4), and titanite (CaTiSiO5), 39K spin-echo spectra for leucite (KAlSi2O6), microline (KAlSiO8), muscovite (KAl2(AlSi3O10)(OH2) and a potassium aluminosolicate glass, and preliminary 73Ge spin-echo MAS spectra for crystalline and glassy germanium dioxide (GeO2).

59Co chemical shift anisotropy and quadrupole coupling for K3Co(CN)6 from MQMAS and MAS NMR spectroscopy.

59Co triple-quantum (3Q) MAS and single-pulse MAS NMR spectra of K3Co(CN)6 have been obtained at 14.1 T and used in a comparison of these methods for determination of small chemical shift anisotropies for spin I = 7/2 nuclei. From the 3QMAS NMR spectrum a spinning sideband manifold in the isotropic dimension with high resolution is reconstructed from the intensities of all spinning sidebands in the 3QMAS spectrum. The chemical shift anisotropy (CSA) parameters determined from this spectrum are compared with those obtained from MAS NMR spectra of (i) the complete manifold of spinning sidebands for the central and satellite transitions and of (ii) the second-order quadrupolar lineshapes for the centerband and spinning sidebands from the central transition. A good agreement between the three data sets, all of high precision, is obtained for the shift anisotropy (delta(sigma) = delta(iso) - delta(zz)) whereas minor deviations are observed for the CSA asymmetry parameter (eta(sigma)). The temperature dependence of the isotropic 59Co chemical shift has been studied over a temperature range from -28 to +76 degrees C. A linear and positive temperature dependence of 0.97 ppm/degree C is observed.

Conformation of alamethicin in oriented phospholipid bilayers determined by (15)N solid-state nuclear magnetic resonance.

The conformation of the 20-residue antibiotic ionophore alamethicin in macroscopically oriented phospholipid bilayers has been studied using (15)N solid-state nuclear magnetic resonance (NMR) spectroscopy in combination with molecular modeling and molecular dynamics simulations. Differently (15)N-labeled variants of alamethicin and an analog with three of the alpha-amino-isobutyric acid residues replaced by alanines have been investigated to establish experimental structural constraints and determine the orientation of alamethicin in hydrated phospholipid (dimyristoylphosphatidylcholine) bilayers and to investigate the potential for a major kink in the region of the central Pro(14) residue. From the anisotropic (15)N chemical shifts and (1)H-(15)N dipolar couplings determined for alamethicin with (15)N-labeling on the Ala(6), Val(9), and Val(15) residues and incorporated into phospholipid bilayer with a peptide:lipid molar ratio of 1:8, we deduce that alamethicin has a largely linear alpha-helical structure spanning the membrane with the molecular axis tilted by 10-20 degrees relative to the bilayer normal. In particular, we find compatibility with a straight alpha-helix tilted by 17 degrees and a slightly kinked molecular dynamics structure tilted by 11 degrees relative to the bilayer normal. In contrast, the structural constraints derived by solid-state NMR appear not to be compatible with any of several model structures crossing the membrane with vanishing tilt angle or the earlier reported x-ray diffraction structure (Fox and Richards, Nature. 300:325-330, 1982). The solid-state NMR-compatible structures may support the formation of a left-handed and parallel multimeric ion channel.

Characterization of the antibody response to pneumococcal glycoconjugates and the effect of heat-labile enterotoxin on IGg subclasses after intranasal immunization.

The antibody response to pneumococcal glycoconjugate (Pnc) was characterized by analyzing pneumococcal polysaccharide (PPS)-- and protein carrier-specific IgG subclass profiles and their relationship. Mice were immunized intranasally (inl) or subcutaneously (sc) with Pnc with mutants of Escherichia coli heat-labile enterotoxin, LT-R72 and LT-K63, as mucosal adjuvants. Subcutaneous immunization with Pnc alone induced predominantly IgG1, whereas native PPS administered sc induced very low IgG titers that were exclusively of the IgG3 subclass. Compared with sc immunization with Pnc alone, inl immunization with Pnc and LT mutants induced significantly higher systemic IgG2a, IgG3, and IgA antibodies to both PPS and the carrier, whereas the IgG1 titers were comparable. There also was a significant correlation between PPS- and protein carrier--specific antibody responses for all IgG subclasses. This demonstrates that LT mutants can be used to both enhance and modulate the antibody response to the PS moiety of glycoconjugate vaccines.

(13)C chemical shift and (13)C-(14)N dipolar coupling tensors determined by (13)C rotary resonance solid-state NMR.

This work explores the utility of simple rotary resonance experiments for the determination of the magnitude and orientation of (13)C chemical shift tensors relative to one or more (13)C--(14)N internuclear axes from (13)C magic-angle-spinning NMR experiments. The experiment relies on simultaneous recoupling of the anisotropic (13)C chemical shift and (13)C--(14)N dipole--dipole coupling interactions using 2D rotary resonance NMR with RF irradiation on the (13)C spins only. The method is demonstrated by experiments and numerical simulations for the (13)C(alpha) spins in powder samples of L-alanine and glycine with (13)C in natural abundance. To investigate the potential of the experiment for determination of relative/absolute tensor orientations and backbone dihedral angles in peptides, the influence from long-range dipolar coupling to sequential (14)N spins in a peptide chain ((14)N(i)--(13)C(alpha)(i)--(14)N(i+1) and (14)N(i+1)--(13)C'(i)--(14)N(i) three-spin systems) as well as residual quadrupolar-dipolar coupling cross-terms is analyzed numerically.

Serum samples from infants vaccinated with a pneumococcal conjugate vaccine, PncT, protect mice against invasive infection caused by Streptococcus pneumoniae serotypes 6A and 6B.

Streptococcus pneumoniae serogroup 6 is an important cause of respiratory tract disease worldwide. Vaccination with 6B polysaccharide induces antibody response to the cross-reacting serotype 6A, but the protective capacity of 6A antibodies induced in infants remains unknown. In this study, passive immunization with serum samples obtained from infants vaccinated with an octavalent polysaccharide protein conjugate vaccine, PncT, protected mice against bacteremia and/or lung infection caused by intranasal challenge with serotypes 6B and 6A. Protective infant serum samples had significantly higher serotype-specific IgG levels and opsonic activity than did nonprotective serum samples. The protective level to either serotype was approximately 1 microg of specific IgG antibodies injected per mouse (corresponding to approximately 0.3 microg/mL). The protection was strongly related to opsonophagocytic antibody levels measured in vitro. These results demonstrate that PncT induces antibodies in infants that protect mice against invasive disease caused by the homologous serotype and by the cross-reacting serotype 6A.