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Biomedical subjects

D J West

Publications and source records attributed to D J West.

At least 19 recordsLinked to original sources
PubMed2001

Persistence of immunologic memory for 13 years in recipients of a recombinant hepatitis B vaccine.

All subjects in this clinical study gave informed written consent, and guidelines of the authors' institution regarding human experimentation were observed in the conduct of the study. A booster dose of vaccine given to 18 adolescents (immunized as children) and 7 older adults immunized 13 years earlier with a 3-dose course of recombinant hepatitis B vaccine induced a strong secondary antibody response, demonstrating that the vaccinees retained immunologic memory for HbsAG. Within one week, booster vaccination induced an 11 to 24-fold rise in the GMT of anti-HBs which continued, reaching 52 to 319-fold after 4 weeks. Significantly even the 5 individuals with less than 10 mIU/ml of anti-HBs prior to the booster all had impressive responses to the booster dose.

Adolescent↗
PubMed2001

Occupational injuries of physiotherapists in North and Central Queensland.

The National Occupational Health and Safety Commission of Australia has identified musculoskeletal injuries in the health industry as a key area of concern. There is little data available on injuries to physiotherapists. This study aimed to investigate the nature, prevalence, job risk factors and consequences of occupational injuries, with particular focus on musculoskeletal injuries, experienced by physiotherapists in North and Central Queensland. A work-related musculoskeletal injury was defined as pain lasting more than three days that the respondent felt was cause by their work as a physiotherapist. Fifty-five per cent of respondents had experienced a work-related injury and 40% had experienced injury in the previous year. The most injured body areas were the low back, hands and neck. Over half (56%) of the initial episodes of injury occurred within five years of graduation. The job risk factors of most concern to injured respondents were sustained demanding postures, manual therapy techniques, repetition, working while injured and excessive workloads. Injured respondents chose to work while injured and not to take time off on workers' compensation or have surgery. Following injury, 38 of respondents changed work settings. Most injured physiotherapists modified their techniques to continue working. Further research is needed to develop effective preventative strategies.

Adult↗
PubMed2001

Light at the end of the Ca(2+)-release channel tunnel: structures and mechanisms involved in ion translocation in ryanodine receptor channels.

RyR and InsP3R are Ca(2+)-release channels. When induced to open by the appropriate stimulus, these channels allow Ca2+ to leave intracellular storage organelles at an astonishing rate. Investigations of the ion-handling properties of isolated RyR channels have demonstrated that, at least in comparison to voltage-gated channels of surface membranes, these channels display limited powers of discrimination between physiologically relevant cations and this relative lack of selectivity is likely to contribute to the ability of Ca(2+)-release channels to maintain high rates of cation translocation without compromising function. A range of ion-handling properties in RyR are consistent with the proposal that this channel functions as a single-ion channel and theoretical considerations indicate that the high rates of ion translocation monitored for RyR would require the pore of such a structure to be short and possess a large capture radius. Measurements of the dimensions of regions of RyR involved in ion conduction and discrimination indicate that this is likely to be the case. In each monomer of RyR/InsP3R, residues making up the last two trans-membrane spanning domains and a luminal loop linking these two helices contribute to the formation of the channel pore. The luminal loops of both RyR and InsP3R contain amino acid sequences similar to those known to form the selectivity filter of K+ channels. In addition the luminal loops of both Ca(2+)-release channels contain sequences that are likely to form helices that may be analogous to the pore helix visualised in KcsA. The correlation in structural elements of the luminal loops of RyR/InsP3R and KcsA has prompted us to speculate on the tertiary arrangement for this region of the Ca(2+)-release channels using the established structure of KcsA as a framework.

Animals↗
PubMed2001

A randomized trial of alternative two- and three-dose hepatitis B vaccination regimens in adolescents: antibody responses, safety, and immunologic memory.

OBJECTIVES: Hoping to increase hepatitis B (HB) vaccination of adolescents, we did the following: 1) studied if modified regimens of the recombinant HB vaccine, Recombivax HB (2 or 3 doses of 5 or 10 microg given over 4 or 6 months), induce protective anti-hepatitis B surface antibody [anti-HBsAb] levels (>/=10 mIU/mL) comparable to the recommended regimen (5 microg at 0 and 1, and 6 months); 2) measured early antibody response after a single dose; and 3) assessed immunologic memory after 2- and 3-dose regimens. DESIGN: One thousand twenty-six adolescents were randomized to 1 of 5 treatment groups (10 microg at 0 and 4 or 0 and 6 months; 5 microg at 0 and 6 or 0, 2, and 4 or 0, 1, and 6 months) in an open trial. Anti-HBsAb was measured in all participants just before and 1 month after the last dose, and at several other times in a subset of vaccinees. Anti-HBsAb response to a booster dose 2 years later was examined to assess immunologic memory in participants vaccinated with 5 microg at 0 and 6 or 0, 1, and 6 months. RESULTS: All regimens induced >/=10 mIU/mL of anti-HBs in >/=95% of vaccinees. Geometric mean titers ranged from 674.8 to 3049.4 mIU/mL. Geometric mean titers were higher with regimens using the following: 1) 10 versus 5 microg; 2) 3 versus 2 doses; and 3) vaccination intervals of 6 versus 4 months. After 6 months, 63.8% of vaccinees given one 10-microg dose had >/=10 mIU/mL of anti-HBsAb versus 41.6% after one 5-microg dose. Participants vaccinated with either two or three 5-microg doses retained robust immunologic memory. CONCLUSIONS: . The results of this study show that a 2-dose regimen of Recombivax HB is as immunogenic and induces immunologic memory as effectively as the recommended 3-dose regimen. A regimen of two 10-microg doses may be of significant benefit for vaccinees who are poorly compliant or deviate from the intended vaccination schedule.

Adolescent↗
PubMed2001

Antibody responses of healthy infants to concurrent administration of a bivalent haemophilus influenzae type b-hepatitis B vaccine with diphtheria-tetanus-pertussis, polio and measles-mumps-rubella vaccines.

OBJECTIVE: To confirm that children given a bivalent Haemophilus influenzae type b-hepatitis B vaccine (bivalent Hib-HB vaccine; COMVAX) concurrently with priming doses of diphtheria-tetanus-pertussis vaccine (DTP), a booster dose of diphtheria-tetanus-acellular pertussis vaccine (DTaP), inactivated or oral polio vaccine (IPV or OPV) and measles-mumps-rubella vaccine (M-M-R(II)) have satisfactory antibody responses to all antigens. DESIGN: 126 healthy 2-month-old infants were scheduled to receive bivalent Hib-HB vaccine concurrently with DTP (2 and 4 months of age), OPV or IPV (random allocation to OPV or IPV at 2 months of age; OPV at 4 and 14 to 15 months of age), DTaP and M-M-R(II) (14 to 15 months of age). A response was judged "adequate" if the lower bound of the 95% confidence interval on the proportion of vaccinees having a critical antibody level was <10 percentage points below prediction. RESULTS: Antibodies to hepatitis B virus surface antigen, H. influenzae polysaccharide, diphtheria toxin, tetanus toxin, pertussis agglutinogens, pertussis toxin (as measured by enzyme immunoassay but not by Chinese hamster ovary cell assay), pertussis filamentous haemagglutinin after a booster dose of DTaP, poliovirus type 2, measles virus, and mumps virus all equalled or exceeded expected levels. Antibodies to rubella virus and pertussis filamentous haemagglutinin (after priming doses of DTP) fell slightly, and in the case of rubella significantly, below predicted levels. Antibodies to poliovirus types 1 and 3 were also below expectation after 2 doses of polio vaccine but were adequate following a third dose of vaccine. CONCLUSION: Concurrent administration of bivalent Hib-HB vaccine with priming doses of DTP, a booster dose of DTaP, OPV, IPV, or M-M-R(II) was well tolerated and, with the possible exception of rubella, did not substantially impair the antibody response to any antigen.

Antibodies, Bacterial↗
PubMed2001

Compliance with hepatitis B virus vaccination in a high-risk population.

OBJECTIVE: To quantify cultural barriers to hepatitis B virus (HBV) vaccination and parental compliance with a specific vaccination protocol among a primarily among population of infants born at a community hospital. METHODS: This study was concurrent with an immunogenicity study of two vaccination schedules and occurred prior to the inception of universal infant vaccination with hepatitis B vaccine (HepB). In this study, parental pairs were interviewed, consent obtained, subjects were randomly assigned to each group, and first immunization was administered in the hospital. Follow-up contacts required for completion were documented. RESULTS: Of 260 eligible parental pairs interviewed, 175 (67%) declined participation, mainly because of fears of vaccine side effects (55%) or ignorance of the hepatitis B virus (HBV) (30%). Of 85 infants enrolled in the study, 28 (33%) were later withdrawn from the study; 13 (46%) of these 28 infants were withdrawn at the request of parents. Each infant who completed the study received 5 postcards, 10 phone calls, and 3 home visits. CONCLUSIONS: Families were unaware of the risk of HBV infection and feared vaccination. Aversion to subjecting an infant to pain was a principal reason for failure to complete the study, and frequent contacts were required to ensure adherence. Existence of a safe and effective hepatitis B vaccine and universal vaccination is unlikely to change deeply felt attitudes against vaccination. Current vaccination strategies must take these prejudices into account.

Cultural Characteristics↗
PubMed2000

Antepartum detection of macrosomic fetus: clinical versus sonographic, including soft-tissue measurements.

OBJECTIVE: To compare clinical and sonographic estimates of birth weights with five new estimation techniques that involve measurements of soft tissue, for identifying newborns with birth weights of at least 4000 g. METHODS: Over 1 year, each woman at or after 36 weeks' gestation and suspected of having a macrosomic fetus had clinical and sonographic estimates of fetal weight (EFW) based on femur length (FL) and head and abdominal circumference, followed by five additional ways to identify excessive growth: cheek-to-cheek diameter, thigh soft tissue, ratio of thigh soft tissue to FL, upper arm subcutaneous tissue, and EFW derived from it. Areas (+/- standard error) of receiver operating characteristic (ROC) curves were calculated and compared with the area under the nondiagnostic line. P <.05 was considered statistically significant. RESULTS: Among 100 women recruited, 28 newborns weighed 4000 g or more. The areas under the ROC curves with clinical (0.72 +/- 0.06) and sonographic predictions using biometric characteristics (0.73 +/- 0.06) had the highest but similar accuracies (P.05). Three of the five newer methods (upper arm or thigh subcutaneous tissue and ratio of thigh subcutaneous tissue to FL) were poor diagnostic tests (range of areas under ROC 0.52 +/- 0.06 to 0.58 +/- 0.07). Estimated fetal weight based on upper arm soft tissue thickness and cheek-to-cheek diameter (areas 0.70 +/- 0.06 and 0.67 +/- 0.06, respectively) were not significantly better than clinical predictions (P.05) for detecting macrosomic fetuses. About 110 macrosomic and nonmacrosomic infants combined would be needed to have 80% power to detect a difference between ROC curves with areas of 0.58 (thigh subcutaneous tissue) and 0.72 (clinical estimate). CONCLUSION: ROC curves indicated that measurements of soft tissue are not superior to clinical or sonographic predictions in identifying fetuses with weights of at least 4000 g.

Adult↗
PubMed1999

Haemophilus influenzae type b conjugate vaccine stability: catalytic depolymerization of PRP in the presence of aluminum hydroxide.

The structural stability of the Haemophilus influenzae type b (Hib) capsular polysaccharide, polyribosylribitolphosphate (PRP) in an aluminum hydroxide adsorbed, polysaccharide-protein conjugate vaccine was monitored using modifications of an HPLC assay developed by Tsai et al. [Tsai C-M, Gu X-X, Byrd RA. Quantification of polysaccharide in Haemophilus influenzae type b conjugate and polysaccharide vaccines by high-performance anion-exchange chromatography with pulsed amperometric detection. Vaccine 1993;12:700-706.]. As applied to products containing PRP conjugated to the outer membrane protein complex (OMPC) from Neisseria meningitidis, this assay allows direct measurement of the total PRP content in very complex samples including commercial vaccine products. In addition, with the use of a high-speed centrifugation step, the assay can be used to directly quantify any PRP that is not conjugated to the OMPC carrier protein. These results provide evidence of what appears to be a catalytic reaction taking place between the phosphodiester bond of PRP and the aluminum hydroxide adjuvant that results in hydrolysis of the PRP polymer into smaller chain lengths and liberation of PRP oligomers from the conjugate particle. The reaction approaches an asymptotic limit after approximately two years at 2-8 degrees C. Clinical studies which span this time period confirm that the modest decrease in conjugated PRP content over time does not impact the overall clinical effectiveness of PRP-OMPC-containing vaccines.

Adsorption↗
PubMed1999

Hepatitis B vaccination of premature infants: a reassessment of current recommendations for delayed immunization.

OBJECTIVE: Current American Academy of Pediatrics and United States Public Health Service Immunization Practices Advisory Committee recommendations for hepatitis B immunization in premature infants weighing <2 kg at birth born to hepatitis B surface antigen (HBSAg)-negative mothers are to delay the initiation of vaccination until such infants reach 2 kg or until 2 months of age. This proposal to delay vaccination at birth in these low-risk infants was based on limited studies not conducted in the United States. We sought to reassess current recommendations to delay administration of hepatitis B vaccine in low-risk premature infants by determining the immunogenicity of early hepatitis B vaccination in a US population and identifying variables associated with poor immunogenicity. METHODS: A total of 148 infants <37 weeks' gestation born to mothers negative for HBSAg were recruited at birth and stratified to three birth weight groups: <1000 g, 1000 to 1500 g, and >1500 g. Recombinant hepatitis B vaccine was administered within the first week of life, at 1 to 2 months of age, and at 6 to 7 months of age. Serum obtained at birth and after the second and third doses of vaccine was tested for antibody to HBSAg. Variables associated with poor response were sought prospectively by collecting demographic and clinical data. RESULTS: A total of 118 subjects (83%) completed the study. Postsecond dose sera were available for 117 infants and postthird dose sera were available for 112 infants. The seroprotection rate (attaining >/=10 mIU/mL HBS antibody) after two doses was low (25%) regardless of birth weight; infants weighing <1000 g at birth had the poorest response (11%). The seroprotection response rate after three doses of vaccine increased with birth weight; infants weighing </=1500 g at birth (groups 1 and 2) had lower rates of response (52% and 68%, respectively) than did infants weighing >1500 g at birth (group 3; 84% response rate). The seroprotection response rate of group 3 infants after three doses of vaccine, although low, could not be differentiated from the response rates reported for full-term infants using 95% confidence intervals. Of all infants who did not achieve protective levels of antibody after three doses of vaccine, 96% (26/27) weighed <1700 g at birth. The geometric mean HBS antibody levels in responders were 88 and 386 mIU/mL after two and three doses, respectively. Of 36 children with a birth weight >1500 g, 33 (91%) achieved levels of HBS antibody >100 mIU/mL after three doses of vaccine, compared with 25/35 (71%) of infants with birth weight <1500 g. Using logistic regression analysis, nonresponders were more likely than were responders to have been treated with steroids (26% vs 9%) and to have had a low birth weight (1037 g vs 1455 g). In addition, the seroresponse rate of black infants was more likely than that of white infants to be associated with poor weight gain (falling off 2 percentile ranks in weight) in the first 6 months of life: 22% of black and 60% of white children who failed to gain weight adequately responded to vaccination, compared with 92% of black and 70% of white children who were growing adequately. Of interest, the only infant with a birth weight of >1700 g who did not make protective levels of specific antibody after three doses of vaccine was 2300 g at birth, but had inadequate weight gain in the first 6 months of life. CONCLUSIONS: This study supports current recommendations of the American Academy of Pediatrics and the Centers for Disease Control and Prevention for delaying the initiation of hepatitis B immunization beyond the first week of life for premature infants at low risk for hepatitis B infection, particularly in newborns weighing <1700 g at birth. In addition, we have identified variables other than birth weight that were associated with an inadequate immune response to early hepatitis B vaccination in premature infants, such as poor weight gain in the first 6 months of life

Analysis of Variance↗
PubMed1998

Present of a toxin in the salivary glands of the marine snail Cymatium intermedius that targets nicotinic acetylcholine receptors.

Presence of a toxin in the salivary glands of the marine snail Cymatium intermedius that targets nicotinic acetylcholine receptors. Toxicon 36, 25-29, 1998.-We present evidence of a neurotoxin from the salivary glands of Cymatium intermedius that displays acetylcholine-like effects on vertebrate (mouse ileum) and invertebrate (molluscan smooth muscle; molluscan heart; leech body wall) tissues. These effects were completely blocked by (+)-tubocurarine (10-100 muM) but not by atropine (up to 200 muM) suggesting that the toxin targets nicotinic-like acetylcholine receptors. This affirms the proposal that this genus may overcome their prey with a paralytic secretion.

Animals↗
PubMed1998

A two-dose hepatitis B vaccine regimen: proof of priming and memory responses in young adults.

This study shows that two doses of a recombinant hepatitis B vaccine (10 micrograms or 20 micrograms of HBsAg per dose), administered 6 months apart to young, healthy adults, can induce an antibody (anti-HBs) response similar to that expected with the standard three-dose regimen of this vaccine given at intervals of 0, 1, and 6 months. While only 46-67% of the vaccinees displayed a protective anti-HBs titer of > or = 10 mIU ml-1 prior to the receipt of the second dose at 6 months, virtually all were primed as 97-99% of the subjects developed such a titer when tested a month after the second dose. Among vaccinees given 10 or 20 microgram doses, respectively, the secondary rise in antibody following the second dose yielded geometric mean titers (GMTs) of 1103 and 2538 mIU ml-1, respectively. The study further demonstrated that a two-dose regimen of vaccination induced strong immunologic memory for HBsAg, as a booster dose of vaccine given 2 years later resulted in a rapid and vigorous anamnestic antibody response.

Adolescent↗
PubMed1998

The pillars of health management education: lessons from the CEE experience.

AUPHA faculty members have had the opportunity to provide health care executive training and to work in partnership with academic institutions in Central and Eastern Europe and in the New Independent States of the former Soviet Union. This article presents some observations on health management education that demonstrate the similarity in issues faced by programs in the U.S. and in CEE. The health management educational partnership program was designed to provide technical assistance to emerging health management programs in the CEE. The partnership program has been mutually beneficial for several reasons. The role of physicians in leadership and the management educational needs that result provide one example of an issue that health management educational programs must address. The emergence of the roles of other health professions and growing contribution that they will make has its parallel in the American ascendance of the role of interdisciplinary team in clinical decision making. The partnership and executive training experiences have caused U.S. partners to focus consciously on pedagogical methods. The nature of the issues faced by emerging CEE health management programs suggests that mutual support among programs in the region after the partnership program is necessary in order to provide a forum for debate. The focus of the debate should continue to be on the role of management in health reform, content of curriculum, research focus and pedagogical methods appropriate for health care management undergraduate and graduate programs. The result will be a strengthening of the health management academic discipline in the region. The future of the AUPHA should predicated on the same principles, the roots from which it has grown.

Curriculum↗
PubMed1998

A BRIDGE partnership model for health management education in the Slovak Republic.

An innovative Health Management Education Partnership (HMEP) was initiated to develop management education initiatives through the exchange of information and ideas. Health education efforts, projects and activities exist between the University of Scranton and three strategic partners in the Slovak Republic: Trnava University, the Health Management School and the University of Matej Bel. The BRIDGE model (Building Relationships in Developing and Growing Economies) utilizes several innovative educational initiatives and strategic projects including a professional journal, faculty development, professional development, curriculum development, certification and accreditation, faculty-students exchange and development of educational materials and modules. The BRIDGE organizational structure is reviewed as well as specific workplan objectives to operationalize the HMEP encouraging mutual cooperation, collaboration and sustainability of efforts. The model stresses implementation, monitoring, and evaluation of all initiatives through a strong community effort, focus on research, deployment of educational resources, curriculum modification, development of interpartnership activities, conferences, workshops, fieldwork experiences and study tours. Applied management practices enhance market-oriented solutions to health care delivery problems emphasizing a focus on privatization and entrepreneurship through education.

Developing Countries↗