Safety and antibody persistence following Haemophilus influenzae type b conjugate or pneumococcal polysaccharide vaccines given before pregnancy in women of childbearing age and their infants.

BACKGROUND: Immunization of healthy women before pregnancy is a potential approach to providing increased levels of maternal antibody to newborns to protect them from infections occurring during the perinatal period and first months of life. METHODS: Healthy nonpregnant Pima Indian women of childbearing age were randomized to receive one of two Haemophilus influenzae type b (Hib) conjugate vaccines [HbOC or Hib-meningococcal outer membrane protein complex (OMP)] or a 23-valent pneumococcal polysaccharide vaccine (PnPs). Infants received Hib-OMP vaccine at 2, 4 and 12 months of age. Vaccine safety and immunogenicity was evaluated in the women and their infants. RESULTS: Anti-polyribose ribitol phosphate antibody titers were significantly higher in women in both Hib conjugate vaccine groups than in the pneumococcal vaccine group throughout the 37-month observation period. Antibody responses to HbOC vaccine were significantly higher than those to Hib-OMP. A subsequent booster dose of each Hib conjugate vaccine induced reactions and antibody responses similar to those of the first dose. Infants born to mothers immunized with Hib vaccines compared with PnPs had significantly higher polyribose ribitol phosphate-specific IgG antibody titers at birth and 2 months of age but lower antibody responses to Hib-OMP at 6 months and similar titers before and after boosting with Hib-OMP at 1 year of age. By contrast women immunized with PnPs did not have significantly elevated concentrations of pneumococcal-specific antibody at delivery, and their infants had pneumococcal antibody titers similar to those of infants born to mothers who did not receive pneumococcal vaccine before pregnancy. CONCLUSION: Hib conjugate vaccine given to women before pregnancy significantly increased the proportion of infants who had protective Hib antibody levels at birth and 2 months of age.

Vaccines to prevent respiratory infection: opportunities on the near and far horizon.

Illnesses caused by respiratory pathogens result in great loss of life, suffering and commitment of resources for treatment. That the suffering and loss of life can be prevented through immunization has already been clearly shown with existing vaccines, such as those for Haemophilus influenzae type b, Streptococcus pneumoniae, and influenza. The emergence of drug-resistant pathogens is making reliance on therapy more expensive and perhaps less successful, accentuating the need to focus on prevention. Although several effective vaccines to prevent respiratory infections currently exist, they are underutilized globally. Improvements in immunogenicity, efficacy, and ease of administration, and lowering the costs of some of the existing vaccines would augment the potential for prevention worldwide. The greatest opportunities for the prevention of respiratory infections will rest with vaccines that will become available in the future.

Interchangeability of conjugated Haemophilus influenzae type b vaccines in infants.

OBJECTIVE: To evaluate the safety and immunogenicity of two Haemophilus influenzae type b (Hib) conjugate vaccines when administered in serial combination. These vaccines consisted of Hib capsular polysaccharide polyribosyl-ribitol phosphate (PRP) conjugated to the meningococcal outer membrane protein (OMP) complex (PRP-OMP) and H influenzae oligosaccharide conjugated to a mutant toxin (CRM197) isolated from Corynebacterium diphtheriae (HbOC). DESIGN: Randomized, double-blind, clinical trial evaluating five Hib vaccination regimens. SETTING: Vaccine Treatment and Evaluation Units and affiliated private pediatric practices at Saint Louis (Mo) University, Vanderbilt University, Nashville, Tenn, and Baylor College of Medicine, Houston, Tex. PATIENTS: A total of 497 healthy 2-month-old infants scheduled to receive routine immunization. INTERVENTION: Participants received either PRP-OMP or HbOC given as recommended by the manufacturer, PRP-OMP at 2 and 6 months, HbOC at 2 months, then PRP-OMP at 4 and 6 months, or PRP-OMP at 2 months and then HbOC at 4 and 6 months. Unconjugated PRP was given at 15 months to evaluate priming. RESULTS: Geometric mean antibody concentrations differed significantly among the groups following the second and third immunizations of the primary series and following booster immunization with unconjugated PRP. On each occasion, the groups receiving serial combinations of PRP-OMP and HbOC achieved mean antibody concentrations that equalled or exceeded those of the groups receiving a single product. Adverse reactions did not vary by group. CONCLUSIONS: The studied sequential combinations of Hib vaccines were safe and at least as immunogenic as either vaccine alone.

Vaccine technologies: view to the future.

The development of vaccines to prevent infectious diseases has been one of the most important contributions of biomedical science. Recent advances in the basic sciences are now fueling the development of a new generation of vaccines that will be based on rational design approaches. Two factors are making this possible: an improved understanding of the microbial factors required for virulence and the nature of the immune response to infection. The status of new vaccine technologies is summarized here.

The economic impact of treatment of severe lupus nephritis with prednisone and intravenous cyclophosphamide.

OBJECTIVE: It has been reported that outcomes are improved in patients with severe lupus nephritis treated with combined prednisone and intravenous cyclophosphamide, compared with those treated with prednisone alone. These findings motivated this analysis of the economic impact of the combined therapy. METHODS: The annual expected incidence of severe lupus nephritis in the year 1988 in the US was estimated to be 1,130. A hypothetical patient cohort of this size was used as the model for the present analysis; the costs of treatment with prednisone alone and with combined prednisone and intravenous cyclophosphamide were calculated and compared. The analysis took into account the expected rate of renal failure with each therapeutic approach, as well as age, sex, and the economic value of working years gained. RESULTS: Although the treatment costs are higher for the combination therapy, the analysis revealed overall savings due to a reduced need for kidney dialysis or transplantation, and the economic value of working capacity gained. Savings attributable to patient care costs were $50.8 million; those attributable to working capacity gained were $42.3 million. CONCLUSION: This analysis indicates that over a 10-year period, as much as $93.1 million per annual cohort is saved by the use of combination therapy for the treatment of severe lupus nephritis.

The effect of thermocycling in microleakage analysis.

The purpose of this study was to evaluate the effect of thermocycling on dye penetration during in vitro microleakage analysis of composites. Fifty non-carious human molars, stored in 75% ethanol, were divided into five groups (N = 10). Each tooth was prepared for a MOD slot preparation using a high speed handpiece and water, one proximal cervical margin in cementum, the other in enamel. The enamel margins were etched, rinsed, dried, and the composite inserted and cured in multiple increments. Group A was not thermocycled (TC) and was immersed in 0.5% basic fuchsin dye for 24 h at 37 degrees +/- 1 degrees C. Group A' was not TC and was immersed in 0.5% basic fuchsin dye for 4 h at 37 degrees +/- 1 degree C. Group B was TC in a water bath and immersed in dye as with Group A, Group B' was TC and immersed in dye as in Group A'. Group C was TC, as in Group B, but in a basic fuchsin dye bath. Thermocycling consisted of 250 cycles, 15 s dwell time each in 5 degrees C and 50 degrees C bath. The teeth were mounted in acrylic, and multiple cross-sections of all surfaces were prepared. Dye penetration was read on a scale of 0 (no leakage) to 4 (leakage to the pulpal floor) and means calculated for each surface and tooth. There was no significant increase of microleakage in restorations when thermocycling was used to simulate temperature extremes, either in dye or water baths, as opposed to restorations which were not thermocycled.

Shear bond strength of ceramic orthodontic brackets to enamel.

The recent introduction of ceramic orthodontic brackets has generated interest among orthodontists. The aim of this investigation was to evaluate the in vitro shear bond strengths to enamel of four ceramic orthodontic brackets and one stainless steel bracket in trials with two separate acid-etching times for enamel. Eighty extracted human central incisors were prepared for bonding to Starfire, Allure, Transcend, Quasar, and stainless steel (in the control group) orthodontic bracket systems. Enamel etching times of 15 seconds and 60 seconds were used. There was a total of 10 groups. After acid etching, one coat of low-viscosity bonding agent was applied and the brackets were bonded to etched enamel with Concise orthodontic bonding resin. The bonded test specimens were stored in distilled water at 37 degrees C for 14 days, after which they were thermocycled for 500 cycles (5 degrees C to 60 degrees C). The bonds were stressed to failure in an Instron machine at a crosshead speed of 0.02 inch per minute. The shear bond strengths were calculated and Weibull analysis was used to obtain a shape factor (the slope of the straight line and a measure of predictability) and the characteristic level (the 63.2% bond strength value of median rank on the strength line) for each group. Predictability and high bond strength, along with other factors, are important in the clinical selection of a bracket system. When either predictability or bond strength was considered independently, several bracket systems, coupled with a particular etch time, had either high predictability or high bond strength. The highest predictability and the highest bond strength were both found with the Allure bracket system.

Posterior composite and glass ionomer/composite laminate restorations: 2-year clinical results.

The purpose of this investigation was to evaluate and compare the clinical performance of two posterior composite materials, and two placement techniques, unlaminated and laminated to glass ionomer base. Forty Class II carious lesions were randomly assigned for restoration with one of two composites: Status or Ful-Fil; and using one of two techniques: with and without a glass ionomer base. In the 20 restorations using the laminate technique, the glass ionomer base covered the dentin and extended to the cavosurface in the gingival third of the proximal box. The restorations were evaluated clinically at 24 hours, 6 months, 12 months and 24 months. The clinical parameters used for the examination were: anatomic form, marginal adaptation, color, secondary caries, marginal discoloration and contact. Bitewing radiographs were taken at 24 hours and at 24 months to evaluate gingival margin discrepancy. Impressions of the restorations were made for fabrication of stone dies. Of the 40 restorations, 38 (95%) were available for evaluation at 24 months. For both materials there was a deterioration in anatomic form, in marginal adaptation, and in marginal discoloration. Anatomic form was significantly worse with Status (P less than 0.05). Of the 20 restorations placed using the laminate technique, two had observable loss of the glass ionomer material. Radiographic radiolucencies were observed for both materials and with both techniques. For the laminate technique, all radiolucencies were between the glass ionomer and the composite. The radiographic observations did not change after the initial evaluation. All the restorations were functioning well at 24 months, but longer observation will be required to determine whether there is a clinically significant difference between the two placement techniques.

Effect of dentin surface roughness on shear bond strength.

The aim of this investigation was to evaluate the effect of dentin surface roughness on the shear bond strength of a dentin bonding agent. Seventy-five dentin samples were divided into five surface preparation groups: (1) 60-grit SiC; (2) 320-grit SiC; (3) 600-grit SiC; (4) 600-grit SiC followed by AI2O3, and (5) 320-grit SiC followed by a #245 carbide bur. The prepared dentin was treated with a dentin primer, and one coat of dentin bonding agent was applied and light-cured for 30 s. Each dentin specimen was mounted in a device with a split Teflon mold (I.D. = 3.5 mm, depth = 5.0 mm). Three increments of a restorative composite were placed, compressed firmly, and light-cured for 30 s in the mold. After 24 h of storage, the bonds were stressed to failure in a mechanical testing machine at a cross-head speed of 0.5 mm/min. Weibull analysis was used to obtain a shape factor and characteristic level for each group. The results showed that, with the possible exception of the 600-grit SiC and AI2O3 group, the grit size used for preparation of dentin specimens for shear bond strength testing in this study did not significantly affect bond strength.

Microleakage of glass ionomer/composite laminate Class V restorations.

The aim of this investigation was to evaluate the effects on microleakage of pretreating dentin with polyacrylic acid (PAA), prior to placing a glass ionomer base/composite laminate restoration. Class V erosion-type lesions with the incisal margin on enamel and the cervical margin below the cemento-enamel junction (CEJ), were prepared in 50 sound extracted teeth. These teeth were divided into five dentin treatment groups: A) 10% PAA; B) 20% PAA; C) and D) 40% PAA; E) no dentin preconditioning. In groups A, B, C and E, a glass ionomer base was placed within 1 mm of the margins. In group D the glass ionomer base extended to the cervical margin. The glass ionomer base and the incisal enamel were etched with 37% phosphoric acid prior to placing a bonding agent and restoring with a composite. The restorations were finished and polished and the teeth were stored in distilled water at 37 degrees C for 7 days. They were thermocycled in 0.5% fuchsin dye for 500 cycles (5 degrees C to 60 degrees C), embedded in epoxy resin, and sectioned at 250 mu intervals through the restorations. The section of each tooth exhibiting the most severe dye penetration along the tooth/restoration interface was evaluated and scored both incisally and cervically: 0 = no leakage; 1 = leakage up to the glass ionomer base; 2 = leakage up to 1/2 the wall length; 3 = leakage exceeding 1/2 the wall length. Cervically, the median leakage for all groups was 3.0. Incisally, the median leakage for all the groups was 0.0.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of dental fluorosis and caries in primary teeth of preschool-children living in arid high and low fluoride villages.

The aim of this study was to determine the degree of fluorosis in the primary dentition and the accompanying caries patterns in groups of preschool-children in high and low fluoride areas. Among 331 coloured children, aged 1-5 years, living in an area with water F concentrations ranging from 2.2 to 4.1 parts/10(6), 82% were caries free and the dmft values ranged from 0 to 15 with a mean dmft of 0.8 +/- 2.1. Varying degrees of fluorosis in the primary teeth were present in 50.6% of the children. In 177 coloured children of similar ages from an adjacent area with 0.2 parts/10(6) F in the drinking water the dmft values ranged from 0 to 20 with a mean dmft of 5.4 +/- 5.8. Only 28% of the children were caries free. None of the children in this area had fluorosis. The caries prevalence was significantly higher in the low fluoride area than in the high fluoride area. The degree of fluorosis found in the primary dentition in the children from the high fluoride area was higher than had been anticipated and was accompanied by a very low caries prevalence.

Dental caries status of Chinese children in Johannesburg, South Africa.

The purpose of this study was to determine the dental health status of a representative sample of Johannesburg Chinese schoolchildren, all 250 attending the only Chinese school in the city. In 18 preschoolchildren, 3--5 years old, 16.7% were caries-free, mean dmft was 7.1 +/- 5.8 and labial caries was present in 33.3%. In 165 primary schoolchildren aged 5--16 years, the mean dmft was 590 +/- 3.2 with 20% of the primary dentition caries-free and the mean DMFT was 2.4 +/- 1.9 4.8% of the primary schoolchildren were caries-free. In 67 high school pupils of 11--17 years, 4.5% were caries-free and the mean DMFT score was 7.1 +/- 3.9. Caries prevalences among the Chinese were similar to corresponding groups of children of Chinese immigrants in the United Kingdom and Malaysia.

Dental caries in South African white children aged 1-5 years.

The dentitions of 499 white preschoolchildren aged 1-5 years from a low fluoride area were examined with mirror and probe. The dmft values ranged from 1.0 +/- 2.0 at 1 year of age to 5.1 +/- 4.5 at 5 years of age while the overall mean for the group was 3.7 +/- 4.1. ""Rampant" caries prevalence varied according to the definition used. It is suggested that for epidemiologic studies rampant caries should be defined as a dmft value of 5 or more and that labial caries should be regarded as a specific entity.

Serum alkaline phosphatase activity in relation to liveweight of lambs.

Groups of lambs were fed four levels of a diet based upon oaten grain. Two groups gained weight rapidly, one less rapidly and the other lost liveweight over a 32-day period. Serum alkaline phosphatase activity was found to be closely correlated to liveweight, in a positive linear manner, in those lambs gaining weight rapidly. This relationship was similar in lambs of R or r blood group. Supplementation of the diet with limestone and or sodium chloride did not influence the relationship. This relationship is considered to reflect the influence of the dietary treatments upon the rate of skeletal metabolism.