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Biomedical subjects

C J Howard

Publications and source records attributed to C J Howard.

195 records · Page 11Linked to original sources
PubMed1972

The production of mastitis in cows by the intramammary inoculation of T-mycoplasmas.

Six milking cows were inoculated with bovine and human T-mycoplasmas and control materials into the udder via the teat canal. Control materials produced only a slight transient cell response in the milk. Bovine T-mycoplasmas produced clinical mastitis in nine out of ten quarters inoculated. Seven developed clinical mastitis together with visible changes in the milk, excretion of T-mycoplasmas and greatly increased cell counts in the milk. In three of these quarters, in two different cows, milk secretion ceased completely. Two quarters in a different cow showed visible milk changes, excretion of T-mycoplasmas and increased cell counts. Two quarters were inoculated with human T-mycoplasmas and neither produced any signs of mastitis.Infection of the udder with T-mycoplasmas did not stimulate high-titre serum antibody levels as measured by the metabolic inhibition test, but whey samples gave high titres in two of the cows that were able to control and resolve the infection.

Animals↗
PubMed1971

Some physical properties of K antigens of Escherichia coli related to their biological activity.

The ability of K antigens from Escherichia coli to inhibit the agglutination of sheep red cells by rabbit antibody has been taken as a measure of the ability of such antigens to render strains of E. coli O-inagglutinable, resistant to complement and to phagocytosis, and to increase their virulence for mice. Analysis of K antigens by chromatography on Sepharose and diethylaminoethyl cellulose columns and by immunoelectrophoresis suggested that agglutination-inhibiting activity was directly related to molecular size rather than charge. The effect of alkali treatment showed inhibitory activity to be independent of K-specific antigenic determinants and confirmed its relation to molecular weight.

Animals↗
PubMedDate not supplied

Incentives and barriers to retinopathy screening among African-Americans with diabetes.

Diabetes-related ophthalmic complications are the leading cause of newly diagnosed blindness among adults. These eye complications are often asymptomatic in the early stages, yet the majority of diabetes patients are not screened yearly. To develop a health promotion intervention to increase the rate of screening for diabetic retinopathy by dilated fundus exam (DFE), we assessed the knowledge and health beliefs related to preventing diabetic eye complications among a sample of African-Americans with diabetes. The study design was cross-sectional, using a telephone interview to collect data. From a random sample of 104 African-Americans with diabetes, 67 (64%) were completed: 54 women; mean age of 58 years. The telephone interview schedule contained items grouped into subscales for Perceived Incentives, Perceived Barriers to getting a DFE, Causes of Eye Problems, Risk of Eye Problems, and Effective Treatments for Eye Problems. Descriptive statistics were used to analyze the quantitative data. Transcribed qualitative responses to the open-ended questions were analyzed for themes. The incentives "having eye problems" and "doctor said it was important to go" each had 91% responding it was an incentive to go for a DFE. Only about one-third agreed that any particular item was a barrier to receiving a DFE (e.g., economic factors). In the subscale for Risk of Eye Problems, "retinopathy" had the lowest level of perceived risk (30%). Only 21% of the sample reported there were effective treatments for retinopathy. Eighty-seven percent reported the faulty belief that "diabetic eye problems have symptoms." Only 36% of the sample said they had heard of retinopathy and of those, only 8% could describe it correctly. Among general response themes were: fear, spirituality (faith and hope), priorities, economic or logistical factors, and external/internal motivation. Perceived incentives for receiving a DFE were acknowledged at far greater rates than perceived barriers. Having a yearly DFE in the absence of symptoms must be emphasized in health promotion materials. There are effective, early treatments for diabetic eye problems, and this information should be used to counter the fear of a dreaded diagnosis with the hope of treatment and cure. Ways of coping with fear of having the exam should be included in health education. DFEs must become a routine yearly exam and not just a reaction to recognized problems. Health education must address the specific needs of high-risk minority populations.

Adult↗
PubMedDate not supplied

Interaction of mycoplasmas and phagocytes.

Aspects of the interaction of certain mycoplasmas with macrophages and neutrophils in vivo and in vitro have been studied using two systems, one involving M. pulmonis in mice and the other involving M. bovis with bovine leucocytes. Studies with M. pulmonis indicated that the disappearance of viable organisms from the peritoneal cavity was not enhanced in SPF mice in which a peritoneal exudate rich in neutrophils had been induced. However, viable M. pulmonis organisms disappeared more rapidly from the peritoneal cavities with exudates containing increased numbers of macrophages. Experiments in vitro studied the opsonic effect of bovine IgG isotypes for bovine neutrophils and alveolar macrophages. Both IgG1 and IgG2 promoted killing of M. bovis by alveolar macrophages but IgG2 was more effective than IgG1 at promoting mycoplasma killing by neutrophils. Further studies in vitro indicated that certain bovine mycoplasma could inhibit killing of Escherichia coli by bovine neutrophils.

Animals↗
PubMedDate not supplied

Mycoplasmas and bovine respiratory disease: studies related to pathogenicity and the immune response--a selective review.

Three species of mycoplasma have been established as being of importance as causes of pneumonia in housed calves, based on pathogenicity studies and frequency of association with the disease. These three species are Mycoplasma bovis, M. dispar, and Ureaplasma diversum. M. bovis is the most pathogenic of these species but the disease outbreaks with which it is associated are sporadic. M. dispar is regularly isolated from pneumonic calves but is also found causing mild superficial and asymptomatic infections of the respiratory mucosa. The bovine ureaplasmas are serologically complex. They are distinct from ureaplasmas isolated from other non-ruminants by PAGE analysis, G + C content of DNA, and serology. A second species within the genus ureaplasma has been proposed to accommodate the bovine ureaplasmas, U. diversum. Control of mycoplasma respiratory infections of cattle based on immunization might be possible. Calves have been immunized against M. bovis and immunity has been related to antibody in the lung. M. dispar appears less immunogenic in calves than M. bovis and this may contribute to its pathogenicity.

Animals↗
PubMedDate not supplied

International student enrollment in US dental hygiene schools.

PURPOSE: The purpose of this study was to determine the international student enrollment in US dental hygiene programs, identify methods used to recruit and retain international students, and describe accommodations used for them. METHOD: A 27-item, closed-ended questionnaire was mailed to all dental hygiene program directors (n = 216) in the US. Data were analyzed using descriptive statistics. RESULTS: Responses were received from 154 dental hygiene program directors for a response rate of 71%. Of the 154 returned questionnaires, 70 (45%) dental hygiene program directors indicated that international students were enrolled in their programs, totalling 4% of the total student population, with female students outnumbering males. The highest international student population came from Canada (42%) followed by Asia (32%), Europe (10%), Central America (9%), South America (3%), and Africa and the Caribbean (2%). Six percent of dental hygiene programs actively recruited international students, 3% had an articulation agreement with institutions outside the US, and 96% did not offer special orientation for incoming international students. CONCLUSION: Research showed a need for professional oral health services in other countries. US dental hygiene programs do not actively recruit nor retain international students. The benefits of US dental hygiene programs actively recruiting and retaining international students would be: 1) international students would be equipped to provide comprehensive, preventive oral health services upon returning to their native country 2) international students would foster a better understanding of cultural diversity, which could transfer to social and professional settings among students in US dental hygiene programs.

Dental Hygienists↗