Controlled Field Study Research Articles

Leeches, Quicksilver, Megavitamins, and Learning Disabilities

The rationale underlying megavitamin therapy for remediating children's learning disorders is discussed. It is concluded that the theoretical arguments put forward for such treatment are unconvincing, based on questionable logic, and wholly unsupported by experimental findings. The need is underscored for an internally valid theoretical foundation and for controlled field studies of such therapies prior to their large-scale clinical use.

Behavioral science and prevention

The present paper explores three questions: 1. What can the behavioral sciences contribute to a general understanding of personal health behavior? 2. What techniques from the behavioral sciences can be used to change personal health behavior? 3. What strategies promise to be most useful in applying the principles of the behavioral sciences to prevention? Although there have been a number of models in the behavioral sciences that are applicable to personal health behavior, there is one comprehensive model that has been developed specifically to explain health behavior at the level of individual decision making. The Health Belief Model is described and its implications for preventive health behavior are explored. Although the model identifies several variables that are important determinants of individual health behavior, taken alone, it does not provide a sufficient base for the planning of intervention strategies. Thus, it is important to identify the social networks that influence individual behavior. It is through these networks that specific informational, persuasional, and behavior modifying techniques must function. Finally, it is suggested that controlled field studies are strategically important in testing the efficacy of specific intervention strategies distilled from the behavioral sciences.

Differences in Actual and Perceived Progress During Early Stages of Economic Development1

It is often asked if “progress”, as defined by an increase in the level of general economic development, is “real”‐especially for people of lower socioeconomic status (SES). This paper investigated the empirical validity of two hypotheses relevant to this question at early stages of economic development. The controlled field study took place in the lowland Philippines. Data provided clear support for the first hypothesis (H‐1), viz, as the level of community development increases, the rate of material improvement for above average individuals is much greater than that for people in lower SES groups. Still, however, things do improve for lower SES people with economic development. Further, the improvements tend to make them express more contentment and economic optimism than their more traditional counterparts (H‐2B), although these data failed to support this belief to the degree they supported H‐1.

Single-Dose Monovalent A2/Hong Kong Influenza Vaccine

A controlled field study to evaluate the efficacy of a single dose of monovalent influenza A 2 /Hong Kong vaccine was conducted among Seattle area school children in late fall of 1968. Concurrent epidemics of influenza A and influenza B occurred from December 1968 through February of 1969. Approximately 14 months after administration of vaccine, an epidemic of influenza due to A 2 /Hong Kong strain occurred in this same population, with the epidemic peak in January 1970. This afforded us the opportunity to examine the long-term effect of the vaccine. Protection lasting 14 months after immunization was evident by (1) significantly less absenteeism from school, (2) 58% reduction of reported influenza-like illness, (3) 72% to 76% reduction in infection rates as estimated by serologic testing, and (4) 80% to 83% reduction in the rate of serologically confirmed influenza illness.

A controlled study to assess the effects of vaccination against Newcastle disease in village chickens

The effect of vaccination against Newcastle disease (ND) in free range village chickens was assessed in a controlled field study. Based on the results of a baseline survey, 12 vaccinated and 12 unvaccinated backyard chicken flocks from two adjacent villages were selected and followed for six months. Serum antibody levels were measured on four occasions. All mortalities were recorded and the cause of death was established by necropsy. Selected ND-suspected cases were subjected to virus isolation, and pathogenicity of two selected isolates was measured in terms of mean death time (MDT) of inoculated chicken embryos. The baseline survey revealed that approximately 90% of the village families reared chickens of which only 11% regularly vaccinated their chickens against ND. Another 14% occasionally vaccinated their chickens and 75% did not vaccinate at all. In the flocks under study, antibody titres increased in vaccinated and unvaccinated chickens. About 75% of unvaccinated and 96% of vaccinated mature chickens (>28 weeks of age) had antibodies to ND virus (NDV), but the level was significantly higher in vaccinated birds. A striking difference in seroconversion was observed in unvaccinated and vaccinated younger birds: 3.3% vs. 55.1% in chicks (<9weeks of age) and 7.3% vs. 80.3% in growing pullets (9-28 weeks of age), respectively. Mortality due to ND was significantly higher in unvaccinated flocks (21.6%) than in vaccinated flocks (4.9%). Most of these mortalities occurred in growing pullets and chicks. Eight selected samples were positive for NDV when subjected to embryo inoculation and haemagglutination inhibition (HI) test. Two of the isolates were further characterized: both were velogenic pathotype with MDT of <60 hours. It is suggested that vaccination against ND could significantly reduce mortality in village chickens. DOI: 10.3329/bvet.v27i2.7555 Bangl. vet. 2010. Vol. 27, No. 2, 56-61

Influenza B in the spring of 1965.

SummaryStrains of influenza B virus recovered from children who had acute respiratory illnesses during the spring of 1965 showed antigenic deviation from the B/Md/ 1/59 strain of influenza virus. This finding was most evident in comparative hemagglu-tination-inhibition tests with chicken antisera but was also shown in the relatively poor antibody response against 1965 B strains compared with homologous virus in children who were given 3 doses of a heptavalent respiratory virus vaccine containing B/Md/1/59 antigen. Further evidence was given in the demonstration of less than expected efficacy of the vaccine in protecting children against influenza B in 1965 in a controlled field study. Sera from normal adults collected in June of 1965 often showed low antibody titers and this was consistent with the sporadic occurrence of influenza B which was recorded in the U.S.A. during the 1964-65 respiratory disease season. The findings in the study may be of value as a guideline for judging the significance of future...

Malaria: Hopeful Results Reported

Even as a newly-supplemented malaria suppressive regimen is evaluated in Vietnam, the search continues for more effective anti-malarial drugs, an Army Medical Corps general told the Congress of Neurological Surgeons. Research has intensified, Brig Gen George J. Hayes, MC, USA, said, as the result of reports from various parts of the world—includnig Vietnam—of strains resistant to established antimalarials. Dapsone, used for more than two decades in treating human leprosy, appeared promising (<i>JAMA</i><b>196</b>: 29 [May 30] 1966) for use against chloroquine-resistant<i>Plasmodium falciparum malaria</i>, Brig Gen Hayes noted, continuing: "Accordingly, a controlled field study was conducted in Vietnam during March and April. "This revealed that continuous supplemental, daily, oral administration of one 25 mg tablet of dapsone to troops exposed to malaria in Vietnam can bring about a 50% reduction in the case rates." <h3>Reduced Relapse Rate</h3> By giving the same dosage of dapsone for 28 days during convalescence, starting

PASSIVE SERUM PROTECTION OF THE INFANT RABBIT AGAINST EXPERIMENTAL CHOLERA.

The recent spread of cholera throughout Southeast Asia has re-emphasized the devastating nature of the disease and the importance of effective techniques for its prevention. Uncertainty still exists as to the effectiveness of cholera vaccine, since it has never been subjected to strictly controlled field studies. Administration of a properly prepared cholera vaccine results in a rise of serum agglutinating antibodies in nearly all recipients (Goodner, 1963), but there is some doubt that serum antibody can be effective against an infection which appears confined mainly to the lumen of the gut (Pollitzer, 1959). FYeter (1956) reported that coproantibody rather than circulating antibody was of importance in protection of the guinea pig against fatal enteric infection with Vibrio cholerae. Jenkin and Rowley (1960) showed that active or passive immunization protects adult rabbits against V. cholerae infection in the ligated intestinal loop and concluded that coproantibodies play a role in protection by functioning as opsonins. Metchnikoff (1894) induced a choleralike diarrheal disease in infant rabbits by means of oral administration of V. cholerae and described the disease in terms which can hardly be improved

Regulatory Activities Concerned with Development of Avian Encephalomyelitis Vaccine

Avian encephalomyelitis (AE) is a virus disease of chickens first observed in 1930 by Jones. Since egg transmission was an indicated source of infection, larger breeding establishments investigated, during the early 1950's, methods of prevention and control. The Animal Inspection and Quarantine Division was first contacted in 1956 regarding a U. S. Veterinary License for avian encephalomyelitis vaccine. The mode of natural transmission and true incidence of the disease had not been determined. Prospective license applicants were discouraged by work required to establish the safety and efficacy of experimental products prior to licensing. Meanwhile the Animal In'spection and Quarantine Division, cognizant of the research efforts and the results, had permitted several interstate shipments of brain-propagated live avian encephalomyelitis vaccine for investigational use. The limited field studies conducted were inconclusive because of failure to provide unvaccinated controls and to check immunity of vaccinates and their progeny by challenge or laboratory procedures. The majority of requests made by individuals who simply wanted to u'se the vaccine and had no desire to conduct a controlled field study were denied. These poultrymen were forced to continue to risk the hazards of AE or find another source of vaccine. Commercial manufacturers of biologicals were not interested in preparing avian encephalomyelitis vaccine. Epizootiological studies established that AE was widespread in the United States and Canada. This work also presented convincing evidence that the progeny of immune flocks did not show as chicks clinical evidence of infection. The demand for AE vaccine increased in 1960. Routine interstate movement of unlicensed vaccine could not be permitted. As a result of a meeting with researchers working on avian encephalomyelitis, it was concluded that live virus vaccine propagated in chicken embryos appeared to offer the greatest advantages. Prospective licensees agreed to withdraw pending license applications for chicken brain-propagated live virus vaccine. Efforts were directed toward stimulating interest by a biologies manufacturer, further evaluating live virus vaccine propagated in chicken embryos, and investigating the incidence of the disease in progeny of resistant flocks. Permits for interstate shipments were granted only for the purpose of evaluating experimental product for licensing. The objectives proposed for field trials included studies on the spread of vaccine virus through the egg and by direct contact to susceptible birds and, if such

Some epidemiological features of breast cancer among males

Mortality and morbidity data for breast cancer in males are reviewed and the following observations are made: 1. 1. The age-specific mortality rates increase exponentially throughout life with a greater rate of increase before 40–50 years of age. 2. 2. The age-specific mortality rates are higher for nonwhites in every age group except for those individuals over 80 years of age. During the period 1939–1958, there was a higher mortality rate for nonwhite males. Whereas the white mortality rates have been slowly declining since 1947, the overall pattern for nonwhites has not changed. 3. 3. In a comparison of breast cancer mortality in nine countries, we observed that for both males and females the rates were lowest for Finland and Japan. 4. 4. The breast cancer mortality ratio is least for the married male and female. However, the striking excess mortality present in the single female group was not observed in the single male, but rather in the widowed and divorced groups. 5. 5. A study of the distribution of cancer mortality among Jews and Christians in the white population of New York City during the period 1953–1958 indicated that the average annual breast cancer death rates were highest for the Jewish males and females. 6. 6. The need for and objectives of a controlled field study of breast cancer in males were emphasized and discussed.

Second field evaluation of bivalent Types 4 and 7 adenovirus vaccine.

Earlier reports 1-5 from this laboratory described the development and evaluation in the field of a formalin-killed bivalent adenovirus 6-8 vaccine of monkey-kidney origin. The vaccine was prepared at the Walter Reed Army Institute of Research, and the evaluation consisted of a controlled field study conducted during the winter of 1956 in 624 newly inducted recruits at Fort Dix, N. J. The vaccine was highly effective, commencing one week after vaccination, and produced a 98% reduction in amount of adenovirus-caused respiratory illness. During the winter of 1957, a second controlled field evaluation of the vaccine was carried out among 8238 recruits stationed at Fort Leonard Wood, Mo. The vaccine employed in this trial was provided by Lederle Laboratories and was prepared under commercial conditions. This paper presents the findings in the field trial at Fort Leonard Wood, compares the potency values of the Lederle and Walter Reed vaccines, and presents data concerning

Evaluation of Red Cross gamma globulin as a prophylactic agent for poliomyelitis. 5. Reanalysis of results based on laboratory-confirmed cases.

In previous reports 1 we presented an analysis of the findings of a controlled field study 2 on the prevention of paralytic poliomyelitis by gamma globulin. The diagnosis of the cases included in these earlier reports was based entirely on rigid clinical criteria previously outlined, 2a since no laboratory data were available at that time. The accuracy of such criteria has never been completely evaluated, because suitable laboratory tests have only recently become available, but errors in etiological diagnosis were to be expected even though only paralytic cases were included. In this paper we are presenting a reanalysis of results based exclusively on laboratoryconfirmed cases. We shall also make reference to the United States Public Health Service reports 3 concerning the general use of gamma globulin in 1953 as they relate to data from our controlled study. LABORATORY METHODS Infection with poliomyelitis virus can be determined by either of two

Potential Value of Islands for Controlled Studies on Upland Game Birds

to be obtained. Unless such knowledge gained in the laboratory can be applied directly or indirectly to the field, its value is academic rather than practical. In the laboratory the wild subjects are confined closely in a strange environment; they generally receive unfamiliar foods in an unusual manner; and they are often exposed to bizarre treatments and much handling. In the wild, by contrast, game birds do not live in narrowly restricted areas, seldom find a mass of one kind of food in one pile, are not force-fed, usually have a selection of food that varies in more ways than can be duplicated in the laboratory, and must meet environmental vagaries and dangers throughout their lives with no assistance from man. Only by carefully controlled field studies conducted in conjunction with laboratory research can knowledge (obtained in the latter manner) be applied to game birds under natural conditions.

H. Pertussis Vaccines: The Effect of Washing and the use of Mouse Protection Tests

Widely divergent results have been reported in field studies on immunization against pertussis with phase I H. pertussis vaccines. Sauer1 has reported a very high degree of protection in children innoculated with the phase I vaccine bearing his name. Kendrick and her associates2 in a thorough and well controlled study over a period of several years have obtained unequivocal evidence of protection with their phase I vaccine. Daughtry-Denmark,3 Silverthorne, Eraser and Hendren,4 Singer-Brooks,5 and Miller and Faber6 in smaller field studies have added data confirmatory to Sauer and Kendrick. On the other hand Doull, Shibley and McClelland7 in a large and carefully controlled field study failed to obtain evidence of protection with their phase I vaccine.