Cumulative Radiation Exposure to Patients Undergoing Arthroscopic Hip Preservation Surgery and Occupational Radiation Exposure to the Surgical Team

PURPOSE

To quantify cumulative radiation exposure in patients undergoing arthroscopic hip preservation surgery and occupational exposure to operating room (OR) personnel during such surgery; a secondary objective of this study was to identify factors affecting radiation exposure in patients undergoing hip arthroscopy.

METHODS

Radiation exposure from all preoperative and intraoperative imaging studies was determined for 52 patients undergoing hip arthroscopy. Cumulative and effective radiation doses were calculated and correlated with pathology and body mass index (BMI). Badge dosimeters were worn by OR personnel to measure cumulative occupational exposure. A highly sensitive portable ion chamber was used to evaluate the radiation scatter during surgery performed on a high-BMI patient and a low-BMI patient to reflect a "worst-case scenario" and "best-case scenario," respectively.

RESULTS

Forty-three patients underwent procedures for femoroacetabular impingement (FAI) and 9 underwent procedures for soft-tissue pathologies (ST). The median cumulative exposure was 8.6 mGy and 5.0 mGy for FAI patients and ST patients, respectively (P = .01). The cumulative effective radiation dose was 490 mrem and 350 mrem for FAI patients and ST patients, respectively (P = .47). BMI significantly correlated with cumulative exposure (P = .0004) and trended toward significance with cumulative effective dose (P = .073). OR staff cumulative occupational exposure was low (9 mrem for the surgeon). Ion chamber data showed that increasing patient BMI resulted in increased occupational exposure.

CONCLUSIONS

The median cumulative effective radiation dose to patients undergoing arthroscopic hip preservation surgery is 490 mrem and results in an excess lifetime risk of death from cancer of 0.025%. Greater BMI correlates with increased cumulative radiation exposure and may increase risk to OR personnel. Occupational exposure to the surgical team from hip arthroscopy ranges from 7 to 9 mrem per 50 hip arthroscopies (+0.0005% excess lifetime risk of death from cancer).

LEVEL OF EVIDENCE

Level IV, diagnostic.

Distal biceps brachii tendon repairs: a single-incision technique using a cortical button with interference screw versus a double-incision technique using suture fixation through bone tunnels

BACKGROUND

Distal biceps brachii tendon repairs performed with a tension slide technique using a cortical button (CB) and interference screw are stronger than those based on suture fixation through bone tunnels (BTs) in biomechanical studies. However, clinical comparison of these 2 techniques is lacking in the literature.

PURPOSE

To perform a clinical comparison of the single-incision CB and double-incision BT techniques.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Distal biceps tendon ruptures repaired through either the single-incision CB or double-incision BT technique were retrospectively identified at a single institution. Patients>1 year out from surgery were assessed for range of motion, strength, and complications, and they completed a DASH questionnaire (Disabilities of the Arm, Shoulder, and Hand).

RESULTS

Patients in the CB group (n=20) were older (52±9.5 vs 43.7±8.7 years; P=.008), had a shorter interval from surgery to evaluation (17.7±5 vs 30.8±16.5 months; P=.001), and were less likely to smoke (0% vs 28.5%; P=.02) compared with the BT patients (n=21). DASH scores were similar between groups (4.46±4.4 [CB] vs 5.7±7.5 [BT]; P=.65). Multivariate analysis revealed no differences in range of motion or strength between groups. More CB patients (30%; n=6) experienced a complication compared with those in the BT group (4.8%; n=1) (P=.04), and these complications were predominantly paresthesias of the superficial radial nerve that did not resolve. There were no reoperations or repair failures in either group.

CONCLUSION

Both the single-incision CB and double-incision BT techniques provided excellent clinical results. Complications were more common in the single-incision CB group and most commonly involved paresthesias of the superficial radial nerve.

A comparison of cortical button with interference screw versus suture anchor techniques for distal biceps brachii tendon repairs

BACKGROUND

Distal biceps brachii tendon repairs performed by a "tension slide technique" with a cortical button and interference screw (CB) are stronger than repairs by suture anchor (SA) techniques in biomechanical studies. However, clinical comparison of the 2 techniques is lacking in the literature.

METHODS

Distal biceps tendon ruptures repaired with either a CB or SA technique through a single incision were identified from 2008 to 2013 at a single institution. Patients more than a year out from surgery completed a Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. In addition, patients were assessed for range of motion, strength, and complications. All assessments were performed by individuals blinded to the surgical technique. Strength and motion values from the operative extremity minus the nonoperative arm values yielded differential values that were averaged and used to compare treatment groups.

RESULTS

The CB (n = 20) and SA (n = 17) groups had similar demographics, except for the time from the surgery to evaluation (18 ± 5 vs 32 ± 15 months, respectively; P = .007). Range of motion differed slightly between the groups. The CB group demonstrated better pronation (0° ± 5° vs -4° ± 10°; P < .05), and the SA group demonstrated better flexion (2° ± 0° vs -3° ± 5°; P < .05) and supination (-2° ± 5° vs -7° ± 12°; P < .05). Strength did not differ significantly between the groups. DASH scores did not significantly differ between the groups with univariate analysis, but multivariate analysis demonstrated slightly better DASH scores with the CB technique (4.5 ± 4.4 vs 10.3 ± 14.9; P < .0009). Complication rates were similar between groups (CB 30%, SA 35%; P > .05).

CONCLUSION

CB and SA techniques provide good clinical results with similar complication rates.

A prepared mind--Ernest Edward Tyzzer's legacy of research into avian diseases

Ernest Edward Tyzzer (1875-1965) was a physician, specializing at first (1902-1916) in cancer research and then from 1916 as a parasitologist. He was born of English parents in Wakefield, Massachusetts, where he lived all his life. Educated in Wakefield public schools, Brown University (Ph.B., A.M., Hon. Sc.D.), and Harvard University (M.D.), he established during his 40-yr career (1902-1942) an international reputation in oncology, pathology, virology, bacteriology, parasitology, and taxonomic zoology in relation to human and veterinary medicine. His contributions to knowledge of avian diseases were outstanding and wide-ranging. Seminal work included: new descriptions of tumors in chickens; the first record of Cryptosporidium in birds; studies on the biology, morphology, in vitro culture, and epizootiology of the blackhead (histomonosis) parasite and its reclassification under a new genus Histomonas; descriptions of eight new taxa of amebae and flagellates in chickens, turkeys, and ruffed grouse; descriptions of seven new species of Eimeria in chickens, turkeys, pheasants, and quail as well as studies on their biology, immunogenicity, virulence, and epizootiology; a description of the trematode Collyriclum in English sparrows; the first record of mycosis in ruffed grouse; the recognition of birds as a source of equine encephalomyelitis infections of humans; the first American record of infectious sinusitis in turkeys and discovery of a curative treatment; and studies of Newcastle disease and avian influenza during the war research program of the 1940s. Application of Tyzzer's histomonosis research to farm practice saved the Massachusetts turkey industry from extinction in the 1920s and significantly influenced the recovery of turkey farming nationally.

The potential contribution of ranolazine to Torsade de Pointe

Ranolazine is a novel anti-anginal agent acting through pharmacologic mechanism of inhibition of the late phase of the inward sodium current. In addition, it is a potent inhibitor of rapid delayed rectifier potassium currents, leading to prolongation of the QT interval. However, ranolazine has not yet described to be associated with Torsade de Pointes despite its QT-prolonging effect. In this case report, we describe a patient on ranolazine who developed Torsade de Pointes and discuss about the potential contribution of ranolazine to the development of Torsade de Pointes.

Distal metaphyseal ulnar-shortening osteotomy: surgical technique

Ulnar impaction is a common condition encountered by hand surgeons. Historically, treatment of this condition has been with wafer resection of the distal ulna, by either open or arthroscopic means, or diaphyseal ulnar shortening osteotomy; however, both of these have the potential for prolonged recovery or a need for additional procedures. Wafer procedures, whether done by open or arthroscopic techniques, can result in hemarthrosis, and diaphyseal osteotomies can require hardware removal. Recently, Slade and Gillon described a technique of ulnar shortening in the osteochondral region of the ulnar head, which offers advantages over previously used techniques. The purpose of this manuscript is to describe this technique, as well as pearls and pitfalls associated with the procedure. To more accurately describe the location of the osteotomy, we have changed the name of the procedure from Dr. Slade's original description to distal metaphyseal ulnar-shortening osteotomy.

Anatomic classification of the endoscopic appearance of the normal appendiceal orifice: a novel tool for recognition and documentation of cecal intubation

Complete colonoscopy for cancer screening requires cecal intubation. Failure to reach and examine the cecum may result in missed right colon pathology. We developed and validated a novel classification scheme for the endoscopic appearance of the normal appendiceal orifice (AO). We analyzed 1,456 AO images and grouped them into four categories based on distinguishing features: "diverticuloid," "umbilicoid," "crescent," and "linear." An expert panel classified the images and modified these categories, combining crescent and linear categories into "curvilinear." A 100-image subset was classified twice by a validation cohort consisting of gastroenterology faculty and fellows. Inter-observer agreement among the expert panel, and intra- and inter-observer agreement among the validation cohort were analyzed using Fleiss' kappa statistic. The distribution of AO images was 67% curvilinear, 19% umbilicoid, and 10% diverticuloid; 85 images (4%) were not classifiable. There was substantial inter-observer agreement among the expert panel (κ, 0.72). Inter-observer agreement among the validation cohort was moderate (κ, 0.53 and 0.55 for the first and second viewing, respectively). Intra-observer κ values among the validation cohort were 0.69 for the overall classification, 0.65 for diverticuloid, 0.70 for umbilicoid, and 0.70 for curvilinear, indicating substantial agreement. This simple, validated classification scheme for the endoscopic appearance of the normal AO can be used both as a research and clinical tool to measure endoscopic quality, improve cecal examination, and document successful cecal intubation.

Pathogenesis of Eimeria praecox in chickens: virulence of field strains compared with laboratory strains of E. praecox and Eimeria acervulina

The pathogenesis in chickens of the apicomplexan Eimeria praecox was compared with that of Eimeria acervulina, using intestinal lesions, mucosal integrity, body weight gain (BWG) and the feed conversion ratio (FCR) as criteria. Characteristics of each species were described by combinations of polymerase chain reaction assays and classic parasitological signs. There were considerable overlaps in lengths, breadths, shape indices and volumes of the oocysts of each species. Both species caused statistically significant reductions in BWG at the lowest inocula tested (500,000 sporulated oocysts per bird of E. praecox and 250,000 of E. acervulina). E. praecox was observed for the first time to cause actual body weight loss and marked increases in FCR, as did E. acervulina. E. acervulina caused gross, white pathognomonic lesions, but E. praecox caused micro-lesions, visible in fresh tissue only with a dissecting microscope. Occasionally, lesions of the Houghton strain of E. acervulina were observed to be rounded, rather than typically "ladder-like". Both species caused villous erosion and atrophy. No mortality occurred in birds receiving up to 1 million sporulated oocysts of either species. Using BWG and FCR as criteria, the virulence of recent field strains of E. praecox from Wales (Tynygongl) and the USA (Raleigh) was compared with English laboratory strains of E. praecox (Houghton) and E. acervulina (Houghton). E. praecox (Tynygongl) was markedly more virulent than E. acervulina (Houghton), which was more virulent than E. praecox (Raleigh) and E. praecox (Houghton).

The effects of zinc deficiency on pancreatic carboxypeptidase activity and protein digestion and absorption in the rat

1. Proteolytic enzyme activities were examined in the pancreas of zinc-deficient and control rats. 2. No change was detected in trypsin-plus-chymotrypsin activity. 3. Carboxypeptidase activity was appreciably lowered in zinc deficiency and returned rapidly to normal on zinc therapy. 4. In experiments in which U-(14)C-labelled Chlorella protein was fed no evidence was obtained which suggested that the reduction in carboxypeptidase activity had limited the rate of protein digestion or absorption. 5. The specific activity of pancreatic protein synthesized during these experiments was appreciably lower in zinc-deficient than in control rats. 6. A higher proportion of the total activity present, in each organ examined, was in the non-protein fraction in zinc-deficient rats.

Anticoccidial vaccination: The absence or reduction of numbers of endogenous parasites from grosslesions in immune chickens after virulent coccidial challenge

Male and female floor-reared chickens were immunized with a live, attenuated anticoccidial vaccine (Paracox) and then, 28 days after vaccination, were challenged with virulent strains of Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria necatrix or Eimeria tenella. The relationship between the post-challenge growth rate and specific gross lesion grades, matched in individual birds, was examined. The numbers of endogenous parasites associated with graded lesions of each species were compared with those in challenged naive control birds. The vaccinated chickens were clinically immune judged by weight gains, but the naive controls reared under the same conditions were unprotected. The mean weight gains of vaccinated, immune birds had lower coefficients of variation than those of unvaccinated, unprotected birds challenged with the same species. Whichever Eimeria species the birds were challenged with, a proportion (5 to 75%) of the challenged, vaccinated, immune birds exhibited some coccidial lesions, mostly graded 1 or 2 (on a scale of 0 to 4); whereas all unvaccinated, unprotected birds had severe coccidial lesions, mostly graded 4. Innumerable endogenous parasites were associated with all lesions seen after challenging unvaccinated, naive birds, but 68% of the gross lesions in challenged, vaccinated, immune birds had no associated parasites, and the remaining 32% had very few. It is concluded that the use of lesion grades alone to assess an anticoccidial vaccine may under-rate its efficacy, and that the occasional presence of gross lesions in commercially vaccinated chickens does not indicate vaccine failure unless performance is also adversely affected. Although in a naive bird gross lesions usually indicate disease, the presence of any gross lesions in a bird judged by performance criteria to be immune may be interpreted as the host's successful repulsion of a parasite challenge.

Risk factors for epistaxis on British racecourses: evidence for locomotory impact-induced trauma contributing to the aetiology of exercise-induced pulmonary haemorrhage

REASONS FOR PERFORMING STUDY

The proposed biological mechanisms for exercise-induced pulmonary haemorrhage (EIPH) are many and varied. Better knowledge of risk factors should lead to achievable measures to reduce the incidence.

OBJECTIVES

To identify risk factors associated with epistaxis following racing in UK Thoroughbreds, to gain possible insights into the pathogenesis of the condition and to investigate the association between epistaxis and race finishing position.

METHODS

The association of epistaxis occurring on UK racecourses between 1996 and 1998 with a wide range of race-, horse- and start-level variables was examined in multivariable mixed effect logistic regression analyses. Four multivariable analyses were conducted, one for all race types considered collectively and one each for flat, hurdle and steeplechase race types considered separately.

RESULTS

Risk of epistaxis was significantly increased for hurdle and steeplechase race types compared to both flat and National Hunt flat races. In 3 of the 4 final models, there was a significant biological trend for increasing risk of epistaxis with increasing ground hardness ('going') and accumulated years spent racing. However, in flat races epistaxis was such a rare outcome (0.33 cases per 1000 starts) that this subset analysis had insufficient power to measure the detectable effect of 'going' as statistically significant. Horses with epistaxis were significantly more likely to have a poorer finishing position than those without blood at the nostrils.

CONCLUSIONS

Findings were consistent with the theory that locomotory impact-induced trauma contributes to exercise-induced epistaxis. Further validation of this hypothesis through application of similar methods to endoscopically visible EIPH and through biomechanical studies is warranted.

POTENTIAL RELEVANCE

Knowledge of significant risk factors should allow formulation of practical measures, such as track watering, to reduce the risks of EIPH and epistaxis in racehorses.

Positive affect is associated with cardiovascular reactivity, norepinephrine level, and morning rise in salivary cortisol

Positive affect was examined as a predictor of (1) cardiovascular reactivity during a sadness and an anger recall task and recovery following the protocol, (2) epinephrine (EPI) and norepinephrine (NOREPI) reactivity and level during the recall protocol, and (3) the diurnal pattern of salivary cortisol. Sample was 328 individuals. Negative affect, age, race, sex, smoking status, income, and BMI were adjusted. During sadness recall, positive affect was inversely related to systolic blood pressure (p=.007) and diastolic blood pressure (p=.049) reactivity, and unrelated to heart rate (p=.226). Positive affect was unrelated to reactivity during anger recall (ps>.19), and was unrelated to recovery at the end of the recall protocol. Positive affect was inversely related to the mean level of NOREPI (p=.046), and unrelated to EPI (p=.149). Positive affect was inversely related to the increase in cortisol 30 min post awakening (p=.042), and unrelated to the evening decline in cortisol levels (p=.174). Positive emotions may be relevant to good health.

A survey of Eimeria species in commercially-reared chickens in France during 1994

In a survey of chicken coccidia in France during 1994, samples of litter were collected from 41 farms. On 31 of these farms, eimerian oocysts were abundant enough to allow monitoring of their numbers in the litter. Peak total oocyst counts on these farms ranged from 16,200 to 1,254,000/g of litter, but no coccidiosis was observed. The chickens reared without anticoccidial agents in their food (poulets biologiques) produced higher and earlier peak oocyst counts in litter than the chickens given medicated food (poulets labels). The oocysts in litter samples from 22 farms (13 poulet biologique, five poulet label, two standard broiler, one breeder and one layer) of the original 41 were identified. Six of the seven eimerian species known to parasitize chickens were found, using combinations of five methods (oocyst morphology, intestinal lesions, enzyme electrophoresis, growth in embryonating eggs and prepatent time). Multispecific infections predominated (95% of 22 farms), up to six species occurring together. Of farms where oocysts were detected, the percentages with each species were: Eimeria acervulina (100%), E. mitis (82%), E. tenella (77%), E. maxima (73%), E. praecox (45%) and E. brunetti (27%). These appear to be the first definite records of E. mitis and E. praecox for France. Although E. necatrix was not found in this survey, it had recently been detected by other workers in France, so that all seven chicken Eimeria species were known to be contemporaneous.

Counting coccidial oocysts in chicken faeces: A comparative study of a standard McMaster technique and a new rapid method

For the assessment of coccidial oocyst production by chickens, some modified form of the McMaster counting method is commonly used. The objective of this study was to evaluate a standard method and to compare it to a new, faster method, in which all the preparative stages before counting are carried out in the same container into which the original faecal sample was collected. A stock suspension containing purified oocysts of all seven valid Eimeria species that parasitize chickens was prepared, from which seven concentrations of oocyst suspensions were made. Since the faecal material in a sample influences the ability of oocysts to float up in a McMaster chamber, the new method was tested to establish the optimal amount of faeces in the original sample. Control oocyst suspensions containing no faeces were also tested, and three series of counts using the new method were compared with the standard McMaster method. The results were statistically analysed by agreement analysis. Repeatability and between-operator variation of both methods were also tested by agreement analysis. Counting by the standard McMaster method underestimated the true number of oocysts. The new method gave counts in agreement with the true number of oocysts if using 1 g of faeces per sample. With 2 g of faeces, counts were obtained that agreed with counts by the standard McMaster method. Both methods showed agreement between repeated measurements. The new method used on a sample containing 2 g of faeces provides a convenient alternative to the standard modified McMaster method. A 1-g faecal sample increases agreement with the true numbers of oocysts. Processing of a sample with the new method is about nine times faster than with the standard method.

Tracing the emergence of drug-resistance in coccidia (Eimeria spp.) of commercial broiler flocks medicated with decoquinate for the first time in the United Kingdom

Decoquinate is a quinolone coccidiostat introduced during 1967 as an in-feed prophylactic for broiler chickens. Despite early drug-resistance problems and its age, the drug is still used commercially worldwide. Decoquinate here serves as a valuable model in a field study that addresses the dynamics and economic impact of the development of coccidial resistance to potent synthetic anticoccidial drugs. The results of this unique, hitherto unpublished, study on the initial emergence of resistance of avian coccidia (Eimeria spp.) to a new drug in the field may be of strategic value in the continued use of decoquinate or the introduction of new drugs. The commercial performance of the first 3-5 crops of broilers to be medicated with decoquinate on each of six farms was monitored during 14 months in 1968-1969, supplemented by assessments of the species, population dynamics and decoquinate-resistance of coccidia isolated from each farm. During the rearing of each flock in a single shed on each farm, oocysts were counted in fresh faecal samples collected on three occasions, and the species were identified by their morphology if possible, supported if necessary by the biological characteristics of infections in chickens. E. acervulina was the most common species, followed by E. mitis, E. maxima, E. tenella and E. praecox. E. brunetti occurred rarely, and E. necatrix was not found. Decoquinate-resistance was evident in several species during the rearing of the first decoquinate-medicated crop on each farm, although clinical coccidiosis did not occur. It was concluded that inherently resistant mutants of E. acervulina, E. brunetti, E. maxima, E. tenella, and probably also E. mitis and E. praecox, were selected from field populations by 6 weeks during their first exposure to decoquinate. During up to four more subsequent crops, cycling of resistant parasites stimulated host immunity, which had no obvious adverse impact on commercial performance. There was no apparent seasonal effect. A hypothesis is proposed to explain the sudden and rapid emergence of quinolone-resistance in the coccidia, and why bird health was not thereby compromised in these circumstances.

Relative virulences of a drug-resistant and a drug-sensitive strain of Eimeria acervulina, a coccidium of chickens

The virulence of a field strain of the chicken coccidian parasite Eimeria acervulina (Boreham I), dually resistant to the chemically unrelated anticoccidial agents decoquinate and clopidol, was compared with that of a drug-sensitive laboratory strain (Ongar) of the same species. Following a single heavy infection (prevented from recycling), both strains exhibited pathogenic effects typical of their species, viz., pathognomonic lesions, adverse effects on body weight gain and feed conversion ratio (FCR), but no mortality. One week after infection, chicks infected with either strain had a statistically significantly worse weight gain than the uninfected control; the Boreham I strain produced more oocysts, and caused slightly more severe duodenal lesions and poorer FCRs than the Ongar strain (all those effects being non-significant). After 3 weeks, there were no significant differences between any cumulative effects of either strain, nor any differences from the uninfected control. However, from 2 to 3 weeks after infection, chicks infected with either strain had a greater feed consumption and growth rate than uninfected chicks. When chicks reared on solid floors were given lighter infections of either strain, which were allowed subsequently to recycle naturally, there were no consistent reductions in weight gains, but feed consumption was higher than that of uninfected chicks. Whatever, the mode of infection, there were no significant differences between the weights of infected and uninfected chicks after 3 weeks, but the FCR of infected chicks was usually poorer than that of uninfected chicks. The difference between the virulences of the Boreham I and Ongar strains was not greater than that between various drug-resistant strains or between various sensitive strains of several Eimeria species recorded in the literature. It is therefore concluded that there was no difference between the virulences of the two strains of E. acervulina that could be attributed to the drug-resistance of one of them.

High-power Yb-doped multicore ribbon fiber laser

A highly elongated double-clad ribbon fiber that comprises a pure-silica inner cladding with transverse dimensions of approximately 1.4 mm by 0.23 mm with a linear array of ten ytterbium-doped cores has been fabricated and operated in a simple laser configuration pumped by two diode stacks. The fiber laser yielded 320 W of output power at a center wavelength of 1045 nm in a combined beam with beam propagation factors of approximately 2 (perpendicular to the array) and approximately 150 (parallel to the array) for 576 W of launched pump power. The slope efficiency with respect to absorbed pump power was 62%. The prospects for further power scaling and improved beam quality and efficiency are discussed.

Physical observation of single step UV-written integrated planar Bragg structures and their application as a refractive-index sensor

We present what is to our knowledge the first demonstration of a potentially low-cost refractive-index sensor based on UV processing. A channel waveguide and a Bragg grating are defined in a single UV processing step, resulting in a buried structure with a well-defined grating period. A subsequent wet etch process located over the Bragg grating opens a sensing window in the device and reveals the grating structure. Sensitivity of as much as 5 x 10(-6) was inferred from our device.

Guidelines for evaluating the efficacy and safety of live anticoccidial vaccines, and obtaining approval for their use in chickens and turkeys

These guidelines are intended to aid those engaged in poultry research in the design, implementation and interpretation of laboratory, floor-pen and field studies for the assessment of the efficacy and safety of live anticoccidial vaccines for immunization of chickens and turkeys against Eimeria species. In addition to efficacy and safety requirements, manufacture, quality control and licensing considerations are discussed. The guidelines do not address subunit vaccines comprising non-viable material, but many of the principles described will be relevant to such vaccines if they are developed in the future. Guidelines are available in some countries for avian vaccines of bacterial or viral origin but specific standards for anticoccidial vaccines in poultry have not, as far as we know, been produced. Information is provided on general requirements of registration authorities (based upon regulations applicable in the European Union and the USA) for obtaining marketing authorizations for vaccines. These guidelines may assist poultry specialists in providing specific information for administrators involved in the decision-making process leading to registration of new vaccines, and are intended to facilitate the worldwide adoption of consistent, standard procedures.