Krill Nyctiphanes simplex gonad affection associated with acute-intensity phyllobothriid plerocercoid infection.

This is the first acute-intensity record of helminths parasitizing the subtropical krill Nyctiphanes simplex Hansen, 1911. We briefly describe the pathology of infection of Phyllobothriidae gen. sp. plerocercoids parasitizing N. simplex in the Gulf of California. Infection occurred with a very low prevalence (P = 0.06%, n = 1563 specimens), although acute-intensity exceeded several hundred plerocercoids crowding the hemocoel in one female host. Nyctiphanes simplex showed inflammatory response of hemocyte-based infiltration, nodule formation, and presumptive melanization. Remarkably, cestodes invade and supplant the gonad, causing atretic oocytes and severe tissue destruction in the gonad likely leading to castration and cell death in connective tissue of the infected organs suggesting that acute-intensity infection exceeds the krill's reaction capacity. Thus, Phyllobothriidae gen. sp. negatively affects the host by depleting its fitness, leading to total castration to prevent/block host reproduction.

Evaluation of the Bifactor Nominal Response Model Analysis of a Health Efficacy Measure.

The bifactor nominal response item response theory (IRT) model, proposed by Cai, Yang and Hansen (2011), provides an extension of Bock's (1972, 1997) unidimensional nominal response model to multidimensional IRT. This model has not been utilized in any published studies since its original development. In this study, the model was applied to data from a sample of college students (N = 799) to evaluate the psychometric properties of a health efficacy measure. The nominal response model has the unique capability to estimate the functioning of each single response category, and higher response categories were found to have better functioning in this study. Poor-functioning categories were identified and combined into their adjacent categories. Items with revised response format showed improved functioning. The bifactor nominal response model is a useful tool for evaluation of bifactor scales with ordered while non-equivalently functioning categories.

Detection of Blastocystis from stool samples using real-time PCR.

We developed a real-time LC PCR assay to detect a 152 bp sequence in an uncharacterized region of the Blastocystis genome. The described assay detected 11 of 11 ATCC strains of Blastocystis from subtypes 1, 3, and 4. Three of three stool samples from Oregon and California military personnel that were negative for Blastocystis by an ova and parasite test as well as a conventional PCR assay were positive for Blastocystis using our real-time LC PCR assay. Diagnosis of Blastocystis infections using this sensitive method, including DNA extraction and real-time PCR, only requires 3 h. The lower limit of detection for Blastocystis in stool using the real-time LC PCR assay was calculated to be 760 cells of Blastocystis per 100 mg of stool, an estimated 760 parasites per reaction. The assay did not cross-react with Ruminococcus hansenii, Anarococcus hydrogenalis, Bifidobacterium adolescentis, Fusobacterium prausnitzii, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, or Lactobacillus acidophilus. Because of the ease of use, sensitivity, specificity, and increase in Blastocystis infections in the USA we believe this assay has the potential to be useful as a clinical diagnosis tool of Blastocystis infection.

The yeast flora of the coast redwood, Sequoia sempervirens.

Only four yeast species could be isolated from young and perannual shoots of the coast redwood tree, Sequoia sempervirens, and from soil beneath the trees, viz. both varieties of Debaryomyces hansenii, Trichosporon pullulans, T. porosum and an unidentified red basidiomycetous yeast.

Primary dapsone-resistant Hansen's disease in California. Experience with over 100 Mycobacterium leprae isolates.

We found that in the years 1978 through 1981 only one of 54 previously untreated patients with Hansen's disease was found to harbor dapsone-resistant Mycobacterium leprae. That single strain was only partially resistant, ie, it was resistant to 0.0001% dapsone in a mouse diet but not to higher concentrations. During the years 1983 through 1988, M leprae from 47 previously untreated patients presenting to clinics in San Francisco, Calif, and Los Angeles, Calif, grew in mice. None of these strains was found to be dapsone resistant. Thus, from 1978 through 1988 only one of 101 M leprae isolates obtained from skin biopsy specimens from patients with leprosy was found to be resistant to dapsone. We have concluded that primary dapsone resistance still does not appear to be a significant problem in California. Owing to the fact that our single resistant case and those reported from international sources are, in general, partially resistant, the potential importance of partial dapsone resistance is discussed.

Primary dapsone-resistant leprosy in San Francisco.

The dapsone sensitivity of strains of Mycobacterium leprae from 54 multibacilliferous untreated leprosy patients presenting to the United States Public Health Service Hospital in San Francisco, California, U.S.A., from 1978 to 1981 was studied by mouse foot pad inoculation. M. leprae from 53 patients were found fully sensitive to dapsone. M. leprae from one patient were resistant to only the lowest dietary level of dapsone, 0.0001%, since growth of the bacilli was inhibited by higher and clinically easily achievable levels. Mouse plasma dapsone levels confirmed the reliability of the drug-containing diets.

Prevalence of disease in Southeast Asian teenagers. Results of screening medical examination at a residential vocational training facility.

Findings on health screening of immigrant Southeast Asian adolescents enrolled at a Federally funded vocational training facility were reviewed for the years 1979-1982. History of or positive skin test for tuberculosis was found in 55%. A heavy parasite burden was found in 46% of the recent Laotian immigrants, but was infrequent in Vietnamese who had been in the United States for several months before testing. Anemia was found in only 5.5%, though an additional 6.5% had findings suggestive of Thalasemia trait. Hepatitis B surface antigen positivity occurred in 16.8% but none had abnormal liver enzymes. One case of leprosy and three cases of idiopathic microscopic hematuria were detected.

Histocompatibility antigens in leprosy.

Results of HL-A typing are presented in 82 patients with leprosy and 50 normal Filipinos from Cebu, and 144 normal Filipino immigrants from the Luzon area. Comparisons of HL-A antigen frequencies among the total patients and normals of Cebu showed no statistically significant differences; however, HL-A10 was increased in frequency among the patients with lepromatous disease compared to the normals, and HL-A5 was increased among the tuberculoid patients compared to the lepromatous patients. None of these comparisons was statistically significant when corrected for the number of antigens tested. Comparisons of HL-A antigen frequencies between normal Filipinos of the Cebu and Luzon regions showed increased W-5 in the Luzon population (corrected p smaller than 0.025).