Search PubMed⌕ Search

Biomedical subjects

M T Rogan

Publications and source records attributed to M T Rogan.

42 records · Page 3Linked to original sources
PubMed1986

In vitro development of hydatid cysts from posterior bladders and ruptured brood capsules of equine Echinococcus granulosus.

A variety of morphological forms developed during monophasic culture of ruptured brood capsules of equine Echinococcus granulosus. Attached to some protoscoleces were small posterior bladders, with a surface ultrastructure of truncated microtriches, and these never developed a laminated layer. In contrast, small free vesicles of similar size and ultrastructure, but devoid of an attached protoscolex, produced a layer by 20-30 days. The surface ultrastructure of both these forms is similar to that of the protoscolex attachment stalk and the brood capsule lining, and posterior bladders and small free vesicles are considered to be derived from portions of the stalk +/- part of the brood capsule lining retained at protoscolex release. Also present were large vesicles interpreted from their size and surface anatomy as ruptured, everted brood capsules. When devoid of attached protosoleces these formed cysts each with a laminated layer, whereas similar vesicles with several attached protoscoleces did not develop a layer, or only very occasionally after 70 or more days. In contrast, a few large vesicles with a single attached protoscolex produced a laminated layer. The possibility that protoscolex attachment to stalk remnants or brood capsules inhibits the cystic development of these structures is discussed.

Animals↗
PubMed1984

Fasciola hepatica: tegumental alterations as a consequence of lectin binding.

Adult flukes, Fasciola hepatica, incubated in Hedon - Fleig saline containing concanavalin A (Con A) for 10 and 45 min, respectively, exhibited severe alterations to tegumental morphology involving increased secretory activity, blebbing of the apical plasma membrane, increased total surface area, and swelling of the basal infolds . The effects of Con A were prevented by the addition of alpha-methyl-D-mannoside to the incubating medium. Similar, but less pronounced, effects were caused by wheat germ agglutinin (WGA) binding. Con A and WGA binding indicate the presence of mannose, glucosamine, or glucose moieties and of N-acetylglucosamine. The effects of lectin binding were similar to the early effects of antibody attachment, and it was considered that accelerated membrane turnover was occurring in both cases. Swelling of the basal infolds was thought to be a result of increased apical surface membrane and/or increased permeability due to lectin binding.

Concanavalin A↗
PubMedDate not supplied

Evaluation of a rapid dot-ELISA as a field test for the diagnosis of cystic hydatid disease.

A rapid dot enzyme-linked immunosorbent assay (dot-ELISA) was developed as a field test for the diagnosis of cystic hydatid disease caused by Echinococcus granulosus. The 30 min test was based on the detection of antibodies to antigen B of hydatid fluid and was carried out using 50 microliters of whole blood in a field assessment in the Turkana region of north-west Kenya. Initial laboratory studies showed antigen B to be preferable to crude cyst fluid, with 94% sensitivity and 90.3% specificity for Echinococcus infections. The field test was rapid, inexpensive and simple to perform and is considered to be a useful back-up to ultrasound scanning.

Antibodies, Helminth↗
PubMedDate not supplied

Cystic echinococcosis in semi-nomadic pastoral communities in north-west China.

In order to determine the prevalence of human cystic echinococcosis (CE) in semi-nomadic traditional pastoralist groups in north-west China, 2 large community studies were undertaken in Altai and Tacheng Prefectures in 1990/91 and 1995/96, respectively. The Kekergash community (Altai) comprised mainly ethnic Kazakhs, whereas the Narenhebuke community (Tacheng) comprised mainly Mongolians. Populations were screened for CE by abdominal ultrasound scan (US) and serological tests. The total prevalence of confirmed human CE was higher in Narenhebuke (2.7%, 49/1844) than in Kekergash (0.9%, 17/1861; P < 0.01). Within each community there was no significant difference of CE prevalence between the Kazakh and Mongolian groups, although Han Chinese exhibited twice the rate of CE (4.9%) in Narenhebuke compared to the dominant Mongolian population. For each community, human CE prevalence increased with age and there was a greater risk associated with the practice of home slaughter of livestock. Dogs were screened for Echinococcus granulosus infection and re-infection levels using a highly specific coproantigen test. The proportion of dogs with positive coproantigen tests was significantly higher in Narenhebuke (36.0%, 50/139) compared to Kekergash (17.8%, 16/90). In Narenhebuke the re-infection levels of dogs, as determined by coproantigen positivity, were higher in the winter quarters (49.4%, 39/79) compared to the summer quarters (18.3%, 11/60; P < 0.01). Furthermore, coproantigen re-test positivity was 25% at 3 months and 29.2% at 7 months. Highest dog coproantigen positivity was obtained over the winter period.

Adolescent↗
PubMedDate not supplied

Classification, follow-up and recurrence of hepatic cystic echinococcosis using ultrasound images.

Ultrasound image and morphological structure of hepatic cystic echinococcosis (CE) were analysed in 277 human cases (385 hepatic hydatid cysts). These included 65 CE cases from community surveys carried out between 1995 and 2000 in 3 countries (China, Mongolia and Jordan) and 212 cases from a clinical hospital survey from Xinjiang, China. A new simplified WHO ultrasound classification for human CE was assessed, and considered useful. It is proposed that type, size and number in particular need to be included in the ultrasound classification of hepatic CE. For comparative purposes 6 categories of type were classified in the study as Type 0 to Type 5 (T0-T5): T0, univesicular without pathognomonic signs; T1, univesicular with pathognomonic signs; T2, cysts with sagging or floating laminated membrane; T3, cysts containing daughter cysts; T4, solid mass or mixed cysts; and T5, cysts with partial or full calcifications. This differs from the WHO classification wherein Type T3 cysts (daughter cysts present) are considered a pathological stage to occur in general prior to the sagging or floating membrane (T2) stage. Recurrent hydatid cysts in the liver were also studied based on morphological structures observed directly from surgical intervention. Case follow-up over 1-5 years since endocystectomy in the community surveys indicated 10% (2/10) recurrence of cysts in the residual surgical cavity. Recurrent CE included 2 (2/4) cases after percutaneous treatment.

China↗