Biomedical subjects

J R Todd

Publications and source records attributed to J R Todd.

39 records · Page 3Linked to original sources

PubMedDate not supplied

Human leukocyte antigen and leprosy: study in northern Louisiana and review.

We examined the relationship of human leukocyte antigen (HLA) phenotype to leprosy in six sporadic cases in northern Louisiana and in the world literature through pooling of the results of several studies. We found that HLA antigens DR2 and DQwl were associated with leprosy in the six cases in northern Louisiana (relative risks, 4.57 for DR2 and 4.53 for DQwl), but the results are not statistically significant. We pooled the Louisiana study and other population studies of HLA and leprosy. The results of the pooling show DR2 and DQwl to be associated with leprosy (relative risks, 2.65 for DR2 and 2.73 for DQwl), and these associations are highly statistically significant (P less than 1 x 10(-8) for DR2 and P = 3.6 x 10(-8) for DQwl). Further, we pooled studies of lepromatous leprosy patients vs. controls and studies of tuberculoid leprosy patients vs. controls and found that DR2 and DQwl are associated with both the lepromatous and the tuberculoid forms of leprosy and that these associations are statistically significant. We consider the associations of DR2 and DQwl in these population studies to be evidence for an HLA-associated genetic influence on susceptibility to leprosy.

Adult↗

PubMedDate not supplied

Comparison of the immunogenicity of hepatitis B vaccine administered intradermally and intramuscularly.

Although hepatitis B vaccine reliably induces immunity to hepatitis B virus, the expense of intramuscular (im) vaccination with this product has limited its use. To determine if a smaller, less expensive, intradermal (id) dose of hepatitis B vaccine would be an effective alternative, we compared the response of antibody to hepatitis B surface antigen (anti-HBs) following im vaccination to that following id vaccination. Volunteers who were seronegative for antibody to hepatitis B core antigen were enrolled in the study and received either im or id vaccine. A total of 108 subjects received three 1-mL im injections of hepatitis B vaccine, and another 110 subjects received four 0.1-mL id injections of the vaccine. Similar rates of seroconversion occurred; greater than or equal to 10 mIU of anti-HBs/mL was noted following either three im or three id vaccinations. Furthermore, 2 years after initiation of vaccination, the serum concentration of anti-HBs for id vaccine recipients was similar to that for im vaccine recipients.

Adult↗

PubMedDate not supplied

Environmental nonhuman sources of leprosy.

Leprosy has been considered to occur only after exposure to a human case. However, evidence has been accumulating that this conventional view is wrong and that an environmental nonhuman source is critical to some human infections with Mycobacterium leprae. Observations, some of which date back to the nineteenth century, support soil, vegetation, water, arthropods, and armadillos (Dasypus novemcinctus) as environmental sources of leprosy. Disparate clinical, epidemiologic, and microbiologic evidence has been critically reviewed in light of the fact that 50%-70% of sporadic cases of leprosy in well-studied populations occur in persons who have had no known contact with human leprosy. Historical data and current information alike substantiate the concept of nonhuman sources of the disease; recent observations with monoclonal antibody have shown that phenolic glycolipid-I antigen, which is unique to the M. leprae cell wall, is present in soil. In the absence of a technique for in vitro cultivation, indirect methods and the body of observations reviewed here persuasively favor but do not prove the existence of environmental nonhuman sources of M. leprae.

Animals↗