[Vaccination against Haemophilus influenzaetype b; why and how?] / Vaccinatie tegenHaemophilus influenzaetype b.

After a development period of around 13 years, in 1993 the vaccination against infections caused by Haemophilus influenzae type b (Hib) was introduced into the Dutch National Immunisation Programme. Before the introduction of the vaccination, the burden of disease was high; every year around 700 children acquired an invasive Hib infection, half of whom developed meningitis. Of those children with Hib-related meningitis, 2% died and more than 8% were left with severe residual symptoms. Furthermore, at least one-third of those who recovered developed learning and concentration problems. Hib also caused other infections such as epiglottitis, osteomyelitis and arthritis. Initially, the conjugated Hib vaccine PRP-T was given as a separate injection. From 2005 onwards PRP-T was included in the combination DTaP-IPV-Hib vaccine, and since 2011 PRP-T has been part of the DTaP-IPV-Hib-HepB vaccine. Although H. influenzae is still around, invasive Hib infections in children now occur only very rarely.

[Measles vaccination: why and how?] / Mazelenvaccinatie: waarom en hoe?

The measles virus is highly contagious and may hit non-immune populations very hard, as observed on remote islands. The first live-attenuated measles virus vaccine was registered in the United States in 1963, and was imported to the Netherlands from 1968 onwards. Production was taken over by the National Institute for Public Health (RIV). Because the burden of disease was still high, measles vaccination was introduced into the Dutch National Immunisation Programme in 1976; since 1987 this has been in the form of the combined measles, mumps and rubella (MMR) vaccination. The MMR vaccine was also initially imported and later manufactured by the National Institute for Public Health and the Environment (RIVM). Since then, measles epidemics have almost exclusively affected unvaccinated populations. Vaccinated individuals are thus well-protected, as are unvaccinated individuals as long as the rate of vaccination in the surrounding population is sufficiently high. Unvaccinated individuals who travel to countries where measles is endemic are still at a higher risk. Recent studies show that measles not only has the classical symptoms, but also damages the immune system.

Motivation of university and non-university stakeholders to change medical education in Vietnam.

BACKGROUND: Both university and non-university stakeholders should be involved in the process of curriculum development in medical schools, because all are concerned with the competencies of the graduates. That may be difficult unless appropriate strategies are used to motivate each stakeholder. From 1999 to 2006, eight medical schools in Vietnam worked together to change the curriculum and teaching for general medical students to make it more community oriented. This paper describes the factors that motivated the different stakeholders to participate in curriculum change and teaching in Vietnamese medical schools and the activities to address those factors and have sustainable contributions from all relevant stakeholders. METHODS: Case study analysis of contributions to the change process, using reports, interviews, focus group discussions and surveys and based on Herzberg's Motivation Theory to analyze involvement of different stakeholders. RESULTS: Different stakeholders were motivated by selected activities, such as providing opportunities for non-university stakeholders to share their opinions, organizing interactions among university stakeholders, stimulating both bottom-up and top-down inputs, focusing on learning from each other, and emphasizing self-motivation factors. CONCLUSION: The Herzberg Motivation theory helped to identify suitable approaches to ensure that teaching topics, materials and assessment methods more closely reflected the health care needs of the community. Other medical schools undertaking a reform process may learn from this experience.

Immunotherapy by intralesional injection of BCG cell walls or live BCG in bovine ocular squamous cell carcinoma: a preliminary report.

Cows of the Dutch Frisian and Maas-Rijn-IJssel breed with histologically confirmed ocular squamous cell carcinoma showed complete regression of the primary tumor in 70 or 60% of the cases after intralesional injection of a BCG cell wall or live BCG vaccine, respectively. Recurrence of the tumor was observed in 57% of the animals treated with BCG cell walls and in 25% of the animals treated with live BCG vaccine. Spontaneous regression was seen in 20% of the untreated cows. In a second control group, radical surgery, the most successful treatment for primary stage I tumors in humans, resulted in a 90% cure. Influence of immunotherapy on metastases could not yet be fully evaluated. White blood cell counts were not changed after therapy. It was not possible to link a favorable response to BCG therapy with the intensity of the delayed type hypersensitivity (DTH) reaction to purified protein derivative of mycobacteriae (PPD) or the formation of antibodies to BCG as determined by a micro-enzyme-linked immunosorbent assay. However, in animals that showed tumor regression, the DTH reaction to PPD had a tendency to persist for a longer period of time. It was concluded that 1) block resection was the best method of treatment for this tumor, 2) a single intralesional injection of a BCG cell wall vaccine was as effective as live BCG vaccine in the induction of complete regression of the primary tumor, 3) in this preliminary study BCG cell wall vaccine was less effective than live BCG vaccine in the prevention of recurrence, and 4) this naturally occurring tumor model is well suited for the study of the influence of BCG immunotherapy in a primary stage I tumor.

Regression of induced keratoacanthomas in anagen (hair growth phase) skin grafts in mice.

Transplants of experimental keratoacanthomas induced in skin grafts which were in the growth phase of the hair follicle cycle (anagen phase) were carried out in immunocompetent and immunoincompetent receipients ("nude" mouse, nu/nu). No differences in gross graft observations were noticed. More than 80% of all keratoacanthomas disappeared postgrafting. This percentage was the same for both groups of recipients. These data are in keeping with a nonimmunological regression of experimental keratoacanthomas. A possible correlation with the hair follicle cycle is suggested.

Antitumor activity, induction of cross-resistance, and nephrotoxicity of a new platinum analogue, cis-1,1-diaminomethylcyclohexaneplatinum(II) sulfate, and of cis-diamminedichloroplatinum(II) in an immunocytoma model in the LOU/M rat.

A newly synthesized platinum analogue, cis-1,1-diaminomethylcyclohexaneplatinum(II) sulfate (TNO-6), was compared with cis-diamminedichloroplatinum(II) (cis-DDP) for antitumor activity and nephrotoxicity. Antitumor activity was determined in an IgM immunocytoma model in the LOU/M rat. Tumor cells were inoculated on the left flank, and therapy was started when a tumor diameter of 10 to 30 mm was reached. At the start of the therapy, the primary tumor had already metastasized to the draining lymph node and liver. Both platinum compounds, dissolved in 5% glucose water, induced an almost complete tumor regression within 10 to 14 days (average, 84% tumor load reduction) and prolonged survival, compared to that of nontreated animals. The antitumor activity induced by repeated i.p. administration of cis-DDP and TNO-6 reached its maximum at a dose of 1.0 mg/kg body weight (twice a week for 7 weeks). This treatment regimen resulted in a highest tolerable dose for cis-DDP of 1.0 mg/kg and for TNO-6 of 2.0 mg/kg. However, when rats were treated with a 2.0-mg/kg dose of TNO-6, no increase in antitumor activity was obtained. For both platinum compounds, tumor recurrence occurred in almost all animals within 2 to 7 days after the maximum tumor load reduction. Tumors that recurred were found to be cross-resistant to both platinum compounds tested but were sensitive to treatment with doxorubicin (Adriamycin). With regard to toxicity, repeated administration of TNO-6 (1.0 mg/kg twice a week for 7 weeks) induced less decrease of body weight than did cis-DDP. For TNO-6, even in the highest dose investigated (2.0 mg/kg twice a week for 7 weeks), no nephrotoxicity was observed on histological examination of kidney and blood urea and creatinine values, whereas for cis-DDP nephrotoxicity was still present in the lowest dose investigated (0.5 mg/kg). From the comparison of the antitumor activity and nephrotoxicity of TNO-6 and cis-DDP, administered i.p. in 5% glucose solution, it is concluded that both drugs have comparable antitumor activity and potency. In contrast to the effects of cis-DDP, no nephrotoxicity was observed with TNO-6; thus, TNO-6 might be a good alternative to cis-DDP in avoiding nephrotoxicity during platinum therapy.

Comparison of NITAG policies and working processes in selected developed countries.

BACKGROUND: Vaccines are specific medicines characterized by two country-specific market access processes: (1) a recommendation by National Immunization Technical Advisory Group (NITAG), and (2) a funding policy decision. OBJECTIVES: The objective of this study was to compare and analyze NITAGs of 13 developed countries by describing vaccination committees' bodies and working processes. METHODS: Information about NITAGs bodies and working processes was searched from official sources from June 2011 to November 2012. Retrieved information was completed from relevant articles identified through a systematic literature review and by information provided by direct contact with NITAGs or parent organizations. An expert panel was also conducted to discuss, validate, and provide additional input on obtained results. RESULTS: While complete information, defined as 100%, was retrieved only for the UK, at least 80% of data was retrieved for 9 countries out of the 13 selected countries. Terms of references were identified in 7 countries, and the main mission for all NITAGs was to provide advice for National immunization programs. However, these terms of references did not fully encompass all the actual missions of the NITAGs. Decision analysis frameworks were identified for 10 out of the 13, and all NITAGs considered at least four criteria for decision-making: disease burden, efficacy/effectiveness, safety and cost-effectiveness. Advices were published by most NITAGs, but few NITAGs published meeting agendas and minutes. Only the United States had open meetings. CONCLUSIONS: This study supports previous findings about the disparities in NITAGs processes which could potentially explain the disparity in access to vaccinations and immunization programs across Europe. With NITAGs recommendations being used by policy decision makers for implementation and funding of vaccine programs, guidances should be well-informed and transparent to ensure National Immunization Programs' (NIP) credibility among the public and health care professionals.

Reliability of the enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of Trichinella spiralis infections in conventionally raised pigs.

An enzyme immunoassay with horse radish peroxidase as marker enzyme for detection of antibodies to Trichinella spiralis in pigs is described. In the enzyme-linked immunosorbent assay (ELISA) quantitation of specific antibodies is obtained by means of peroxidase labeled anti-species-immunoglobulin in antigen-coated tubes. The enzyme remaining in the tube after washing provides a measure of the amount of specific antibodies in the serum. A crude saline extract of T. spiralis muscle larvae served as antigen, 5 mug protein/ml being a satisfactory concentration. Lyophilization of antigen had no adverse effect on sensitivity. To decrease background staining the use of an optimal conjugate dilution was important. Adding bovine serum albumen to the conjugate was essential to decrease background reactions. Suitable substrate incubation times were studied. Washing was performed with tap water and Tween 20. In experiments with conventionally raised slaughter pigs infected with different numbers of T. spiralis larvae a positive correlation was found between initial dose of larvae and amount of antibodies detected by ELISA. Compared with immunofluorescence (IF) ELISA was more sensitive. IF yielded positive results in 11 out of 34 infected animals, whereas ELISA results were positive in 27. To evaluate ELISA under practical conditions extinction values of sera from infected and non-infected conventional pigs were compared with the highest extinction value in a group of 74 negative conventional pig sera. The relatively high background reaction of some of these negative sera decreased the number of positive practical ELISA results from 27 to 19 out of 34. In 1 out of 10 non-infected animals a false positive practical ELISA result was obtained.

Mechanization of the enzyme-linked immunosorbent assay (ELISA) for large scale screening of sera.

An on-line routing system (including dispensers, washing device, spectrophotometer, carts, elevators and identification device) for macro-ELISA is described. The system enables processing of 4,000 sera daily by 2 persons. Test results are presented on a data sheet as a combination of identification number and extinction value.

Molecular analysis of selection for benzimidazole resistance in the sheep parasite Haemonchus contortus.

The molecular basis for the resistance of the sheep parasitic nematode Haemonchus contortus to the benzimidazole (BZ) group of anthelmintics was investigated. Three BZ-susceptible and three resistant populations from different geographical locations were characterized with respect to the egg-hatch assay with thiabendazole (TBZ), mebendazole (MBZ) binding tests and restriction fragment length polymorphism (RFLP) after Southern blotting. Cloned H. contortus alpha- and beta-tubulin genes were used as probes to analyze the RFLPs of genomic DNA prepared from mixtures of infectious larvae (L3) or adults. The susceptible populations showed, with both alpha- and beta-tubulin probes, 2 to 6 different fragments, depending on the restriction enzyme used. The three resistant populations showed as many fragments with the alpha-tubulin probe as the susceptible populations, but when probed with beta-tubulin only 1 or 2 fragments were visible, but always less than in the susceptible populations. An in vitro selection experiment was carried out using a susceptible population that was isolated in the laboratory before BZ came on the market. The results showed that after two selections with increasing amounts of TBZ, the population had become resistant, according to the egg-hatch assay values and MBZ binding assay. Using RFPL, the number of beta-tubulin probe reactive DNA fragments was reduced from 5 to 1. Analysis of the DNA of individual male adults of susceptible populations indicated a heterogeneity among the individual worms regarding the number of beta-tubulin probe reactive fragments (1 to 4) and frequency of the specific fragments. Usually, only one specific fragment (9 kb) was found in the resistant individuals. This 9-kb fragment was already present in some individuals in the susceptible population although it was in combination with other fragments. This would imply that genes conferring BZ resistance were present in H. contortus populations before BZ came on the market, and could explain the fast selection for BZ resistance in the field.

Experience with a Dutch kveim suspension in men and guinea pigs.

A Kveim antigen was prepared according to the Chase-Siltzbach method from the spleen of a patient with sarcoidosis. This antigen was tested in a number of patients with sarcoidosis or possible sarcoidosis and also in a number of non-sarcoid patients. Several lots prepared from this spleen were compared, yielding differences in reactogenicity. Maybe this can be explained by heterogeneity of the spleen. An animal model (the BCG-presensitized guinea pig) is presented that may be applicable for a preclinical evaluation of lots of Kveim antigen.

Application of immunofluorescence and immunoenzyme methods in the serodiagnosis of Trichinella spiralis infection.

To detect antibodies to T. Spiralis in sera, the IF methods with the cuticle of T. spiralis larvae (the tube test) was compared to the cryostat method. In the latter method, cryostat sections were prepared from isolated T. spiralis larvae or from tongue or diaphragm musculature in which encysted T. spiralis larvae were present. In this case, both cuticle and internal structures were employed as antigenic sites. The cryostat method proved to be more sensitive than the tube test. With the cryostat method, specific antibodies were detected in sera of experimentally infected mice 14 days after infection, whereas with the tube test, antibodies were detected on Day 24 postinfection and consistently thereafter. The enzyme-linked immunosorbent assay (ELISA) was then studied. Quantitation of specific antibodies was achieved with alkaline phosphatase- or peroxidase-labeled antispecies immunoglobulin in antigen-coated tubes. The enzyme that remained in the tube after washing provided a measure of the amount of specific antibodies in the serum. A saline extract of T. spiralis larvae served as the antigen. In the experimental models studied (T. spiralis-infected rabbits and pigs), ELISA proved to be more sensitive than IF. At Day 3 postinfection and thereafter, specific antibodies could be detected. ELISA was modified to satisfy requirements for routine application.

Application of the enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of human African trypanosomiasis (sleeping sickness).

An enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of human African trypanosomiasis (sleeping sickness) is described. A crude extract of a Trypanosoma brucei suspension which was purified from all blood components was used as antigen. In rabbits experimentally infected with T. brucei or T. rhodesiense both homologous (anti-T. brucei) and heterologous (anti-T. rhodesiense) Trypanosoma antibodies could be detected with ELISA using T. brucei as antigen. The sensitivity of ELISA was comparable with that of the immunofluorescence (IF) technique. Sera of patients with sleeping sickness were examined with ELISA and IF. It proved possible to discriminate between groups of individuals with and without trypanosomiasis. Cross reactions were only observed with serum from a patient in which antibodies to Leishmania were detected. No cross reactions were observed in sera from patients with malaria, toxoplasmosis, schistosomiasis, or echinococcosis. ELISA represents a good alternative to IF in the serology of African trypanosomiasis, and may be particularly suitable for mass screening purposes.

Low doses of interleukin-2 can cure large bovine ocular squamous cell carcinoma.

Four cows bearing large Ocular Squamous Cell Carcinomas (BOSCC) were treated by 10 intratumoral injections (Monday-Friday for 2 consecutive weeks) of 200,000 U Interleukin-2 (Cetus). Tumors regressed in 2 out of 4 cases. This result shows that even large tumors may regress after local IL-2 treatment.

Immunotherapy of bovine ocular squamous cell carcinoma: isolation, culture and characterization of lymphocytes present in the tumor.

Bovine ocular squamous cell carcinoma (BOSCC) is sensitive to intralesional immunotherapy with BCG or recombinant human IL-2 (rhIL-2). The mechanism of tumor regression is as yet unclear. Alterations in the concentration of IL-2 (and possibly other factors) in the tumor, due to regional injection or induction by BCG, may induce killer cell activity and thus tumor regression. To investigate this, lymphocytes were isolated by mechanical fractionation of biopsies of BOSCC. Growth, phenotypical, and functional characteristics were studied. TIL could be isolated and grown from all biopsies of BOSCC. An estimated increase in cell number of 50-150 fold was observed during 5-7 weeks of culture. FACS analysis of a limited number of the TIL cultures showed a characteristic shift in phenotypes until day 28 of culture. CD2+ cells (50-70%), and as a consequence of this CD2- cells, remained stable in number. The number of CD8+ cells increased. CD4+ cells were detected in low numbers by day 28. Prolonged culture resulted in an increase of CD2- gamma delta + cells, CD2+4-8- cells, and occasionally of both CD8+ and CD2+ cells. In 51Cr release assays TIL showed cytotoxicity for BOSCC-derived tumor cell lines in general, which increased transiently by cocultivation with tumor cells. Killing of YAC-1, and P815 was far less efficient. Preferential killing of autologous cell lines was not seen. In conclusion, TIL from bovine ocular squamous cell carcinomas can be cultured in the presence of rhIL-2, which induces cytotoxic activity for BOSCC-derived tumor cells. Cells responsible for killing in vitro and potentially for regression of the tumor after immunotherapy with BCG or rhIL2 cannot yet be identified. Depletion and blocking experiments are being conducted in order to identify the cells (CD2+8+, CD2-gamma delta + or other CD2 +/-) responsible for killing.

Serum opsonic activity and neutrophil phagocytic capacity of newborn lambs before and 24-36 h after colostrum uptake.

Neutrophil (PMN) counts, immune complex (IC) uptake by PMN, and serum opsonising activity for promoting yeast uptake were used to evaluate infection clearing capacity in 16 lambs prior to colostrum feeding (two lambs fed bovine colostrum, 14 suckled lambs) and at 2 days of age. At 2 days of age lambs had more circulating PMN than they had prior to colostrum uptake (P less than 0.01). Colostrum feeding caused a significant increase in the percent of lamb PMN phagocytosing IC, although at Day 2 the percent phagocytosis was significantly lower (32.2%) than for adult controls (90%). Yeast opsonophagocytosis was greater when 24-36 h post-feeding serum was the source of opsonin than when pre-feeding serum was used (P less than 0.001). When adult serum was the opsonin, yeast opsonophagocytosis was approximately twice the phagocytosis mediated by 24-36 h post-feeding serum. The peripheral neutrocytosis and the enhancement of opsonophagocytosis generated by absorption of either ovine or bovine colostrum did not differ. The results of this study suggest that the parameters evaluated may be used for indicating the presence (or absence) of passively acquired protective immunity.

K88 variants K88ab, K88ac and K88ad in oral vaccination of different porcine adhesive phenotypes. Immunological aspects.

Sows of different adhesive phenotypes were vaccinated orally during the last 4 weeks of gestation with K88-positive Escherichia coli. Sows susceptible to adhesion by the K88 variant of the vaccination strain produced a significant IgA-class specific anti-K88 response in colostrum and milk and post-farrowing serum. Indications for an IgM and IgG-class specific anti-K88 response were also found in this group but only in milk. In sows resistant to adhesion by the K88 variant of the vaccination strain only an IgA-class specific anti-K88 antibody response was found in mammary secretions and in post-farrowing sera, but titres did not reach the high values of the former group. The response in the second group was attributed to the frequent administration of large quantities of K88-positive E. coli which to some extent can be compared with a colonization effect. Specificity for the serological components of the K88 variants was detectable in colostral IgA of sows susceptible to the vaccination strain only.

Detection of canine cytokine gene expression by reverse transcription-polymerase chain reaction.

Further characterization of the canine immune system will greatly benefit from the availability of tools to detect canine cytokines. Our interest concerns the study on the role of cytokines in canine visceral leishmaniasis. For this purpose, we have designed specific primers using previously published sequences for the detection of canine IL-2, IFN-gamma and IL10 mRNA by reverse transcription-polymerase chain reaction (RT-PCR). For IL-4, we have cloned and sequenced this cytokine gene, and developed canine-specific primers. To control for sample-to-sample variation in the quantity of mRNA and variation in the RT and PCR reactions, the mRNA levels of glyceraldehyde-3-phosphate dehydrogenase (G3PDH), a housekeeping gene, were determined in parallel. Primers to amplify G3PDH were designed from consensus sequences obtained from the Genbank database. The mRNA levels of the cytokines mentioned here were detected from ConA-stimulated peripheral mononuclear cells derived from Leishmania-infected dogs. A different pattern of cytokine production among infected animals was found.

Antitumor effect of locally injected low doses of recombinant human interleukin-2 in bovine vulval papilloma and carcinoma.

In many human clinical trials and in various animal tumor models, the antitumor effect of high doses of systemically applied interleukin-2 (IL-2) is tested. Our studies focused on the effects of low doses of locally injected IL-2. In this paper, the effect of local injection of low doses of IL-2, i.e. a total dose of 25,000-50,000 units, into papillomas or carcinomas of the bovine vulva is described. In 19 out of 23 (83%) cows treated with IL-2 an effect on the tumor load was observed; in three of these animals, complete regression was obtained. In the majority of cases, regression was not restricted to the tumors injected with IL-2.

The United States--The Netherlands Round Table Conference on immunization. Summary report.

A group of public health scientists from the United States and The Netherlands met at a Bicentennial Round Table Conference December 1-2, 1982, to discuss the latest developments in immunization against infectious diseases, focusing on pertussis, poliomyelitis, measles, and rubella. The major differences in immunization practices in the two countries are: (a) In The Netherlands, inactivated polio vaccine is used exclusively; in the United States, the oral polio vaccine is used. Polio-myelitis has virtually disappeared from both countries. (b) In The Netherlands, the pertussis component of DTP (diphtheria, tetanus, pertussis) is not given to children over the age of 1 year, whereas in the United States, it is given to children up to their seventh birthday. (c) Rubella vaccine is given only to girls at ages 11-12 years in The Netherlands, but to all children at ages 12-15 months in the United States. (d) Mumps vaccine is not administered to children in The Netherlands, but in the United States it is given routinely to children at 12-15 months (in combination with measles and rubella vaccine). The participants concluded that both the United States and The Netherlands have effective immunization programs that have significantly reduced the impact of these diseases.