Atoxoplasma (Apicomplexa: Eimeriorina: Atoxoplasmatidae) in the greenfinch (Carduelis chloris)

Merozoites of an Atoxoplasma species were present within parasitophorous vacuoles in the cytoplasm of leucocytes in the blood vessels in the small intestine of the greenfinch (Carduelis chloris). The merozoites indented the nucleus of the leucocytes. Merozoites, macrogametes, and microgamonts were present in the epithelial cells of the intestines. No merogony was observed. Experiments provided circumstantial evidence linking disporocystid-octozoic oocysts with the blood and intestinal infections.     

Manganese in the shell of Centropyxis (Rhizopodea: Protozoa)

The proteinaceous shells of Centropyxis hirsuta contain a relatively high concentration of manganese in an amorphous state. The concentrations of manganese fill the alveoli which are characteristic of the shell structure. Observations based on cultured animals and subsequently examined by X-ray diffraction, a solid state energy dispersive X-ray analyser, and an analytical electron microscope, lead to the conclusions that manganese is selectively absorbed by Centropyxis hirsuta and deposited in the shell.     

The genus Myxidium (Protozoa: Myxosporida) in macrourid fishes

A physical model approach was used to investigate cholesterol gallstone dissolution kinetics in simulated bile. Critical experimental and theoretical investigations simulating in vivo conditions showed that, in the bile acid-lecithin solutions, there is a significant interfacial barrier for both cholesterol gallstone and cholesterol monohydrate pellet dissolution. In the present study, the rotating-disk dissolution method and the accompanying Levich theory were applied to assess the contributions of the diffusion convection mass transfer resistance and of the interfacial barrier to the overall kinetics. Cholesterol dissolution rates in bile acid solutions were about 2-20 times slower than diffusion-controlled rates depending upon the degree of agitation. As found in previous studies, these rates in the presence of sufficient concentrations of dissolution accelerators approached the theoretical diffusion-convection-controlled rates. To account for the much slower dissolution rates in bile acid-lecithin solutions, two possible kinetic interpretations were investigated. The first is based upon slow crystal-micellar solution interfacial kinetics, and the second is based upon a slow rate of cholesterol solubilization in the aqueous diffusion layer. For the latter, an analytical mathematical solution was obtained.     

Myxosporida (Protozoa) in California rockfish, Sebastes spp

Six genera and 15 species, 2 new, of myxosporida were recovered from 14 species of California marine rockfish, Sebastes. The spores of Leptotheca sebasta sp. n. are arched with thick, equal shell valves and large round polar capsules. They are greater in width and sutural diameter and more crescentic than L. latesi. Ceratomyxa sebasta sp. n. is crescentic in shape with equal shell valves. The spores of C. sebasta are shorter in sutural diameter, larger in width, and less crescentic than C. hokarari.     

Recommended nomenclature for solvent extraction (liquid-liquid distribution)

Recommendations are presented for nomenclature in solvent extraction chemistry and processes including definitions, preferred symbols, and comments on the acceptability or otherwise of certain terms and their use in particular situations. An attempt has been made to generalize the definitions to include any system of two immiscible liquid phases.     

Sarcocystis buffalonis n.sp. (Protozoa: Sarcocystidae) from the water buffalo (Bubalus bubalis) in Vietnam

Sarcocystis buffalonis n. sp. is proposed for a species forming thick-walled, macroscopic sarcocysts in skeletal muscles and the esophagus of the water buffalo (Bubalus bubalis). Sarcocysts of S. buffalonis were found in 68 (10.5%) of 647 buffalo carcasses examined grossly at slaughter in Ho Chi Minh City in southern Vietnam. Sarcocystis buffalonis sarcocysts were 1-8 mm long and 0.1-0.5 mm wide. The cyst wall was 3-7.7 microns thick and had palisadelike villar protrusions that were constricted at the base, expanded laterally in the mid-region, and tapered distally. The villar protrusions contained microfilaments and electron-dense granules. Sarcocysts of Sarcocystis fusiformis, the other well-known macroscopic species occurring in water buffalo, were also found in 60 of the 68 animals infected with S. buffalonis. Sarcocysts of S. fusiformis were thin walled and had characteristic cauliflowerlike villar protrusions. Two of 7 cats fed isolated S. buffalonis sarcocysts were found to have 12 x 8 microns sporocysts in their intestine or feces 10 days after inoculation.     

Enteric coccidia (Apicomplexa) in the small intestine of the northern spotted owl (Strix occidentalis caurina)

Sporulated oocysts (mean dimensions = 13.0 x 10.8 microns) and sporocysts (11.3 x 5.5 microns) of a coccidian resembling Frenkelia sp. or Sarcocystis sp. were present in the lamina propria of the small intestine of a naturally-infected northern spotted owl (Strix occidentalis caurina) collected near Medford, Oregon (USA). Dimensions of these oocytes and sporocysts appear to be considerably smaller than those from other sarcocystid species with avian definitive hosts. Additionally, numerous developmental stages and unsporulated oocysts (mean dimensions 22.8 x 17.8 microns) of a possible species of Isospora also were observed in the intestinal epithelium. This constitutes the first report of enteric coccidia from spotted owls. Neither parasite appeared to cause the death of the bird.     

Life cycle, host restriction and longevity of Babesiosoma mariae HOARE, 1930 (Apicomplexa: Dactylosomatidae)

Morphometric and morphological observations on B. mariae in an experimentally infected fish (using the leech vector Batracobdeloides tricarinata for the first time) revealed that three successive types of merogonic cycles occurred within the fish erythrocytes. The third cycle produced merozoites destined to become gamonts. The gamonts were somewhat larger than merogonic stages and comprised the majority of the parasitic stages during parasitaemia for up to 7 months. In the leech crop gamonts released from the fish blood became associated in syzygy and fused. The formed zygote underwent sporogony within the gut tissues and up to 8 sporozoites budded simultaneously from the periphery of an irregularly shaped oocyst. The sporozoites underwent merogony typical as that of erythrocytic merogony mainly in the salivary tissues. The merozoites either initiated a further cycle of merogony or moved towards the proboscis. The babesiosomes survived in the leech over a period of 9 months involving 7 meals after the initial meal provided the fasting period did not exceed 60-90 days. Survival was attributed to residual stages in the salivary glands. Cross transmission experiments between fishes via B. tricarinata revealed that the fish babesiosomes were not host specific. Previously described African fresh water fish dactylosomatids were indistinguishable from each other and on the basis of the current results, they are regarded as a single species Babesiosoma mariae.     

Amplification of genomic DNA fragments of Sarcocystis muris (Apicomplexa) cyst merozoites encoding a thiol (cysteine) proteinase

Parasites of the phylum Apicomplexa (Sporozoa) cause diseases such as malaria, toxoplasmosis, or intestinal coccidiosis. Invasive stages possess typical apical organelles such as dense granules that harbor a broad range of polypeptides that are believed to take part in the parasite-host cell interaction. In previous studies a 26-kDa polypeptide of dense granules from Sarcocystis muris cyst merozoites (bradyzoites) was characterized as a thiol (cysteine) proteinase. In this paper a method is demonstrated to amplify DNA fragments from genomic DNA of S. muris cyst merozoites by polymerase chain reaction, which probably code for the 26-kDa antigen.     

Ceratomyxa sparusaurati (Protozoa:Myxosporea) infections in cultured gilthead sea bream Sparus aurata (Pisces:Teleostei) from Spain: aspects of the host-parasite relationship

C-Raf is a an essential member of the growth factor-ras pathway and a target for intervention strategies aimed at blocking cell proliferative responses. Excessive smooth muscle proliferation is considered one cause of the arterial closure in restenosis. Because of the similarity to the human cardiovascular system, a useful current animal model of the disease is a baboon model. As a foundation for animal studies employing antisense oligonucleotides, efforts were made to characterize the molecular and cellular biology of the baboon system. The nucleotide sequence of baboon c-raf cDNA was determined. Antisense phosphorothioate oligonucleotides specific to the 3'-UTR of c-raf mRNA from human and baboon were compared using primary baboon smooth muscle cells in culture. A particular human antisense oligonucleotide, referred to as ISIS 5132, was different by only 2 of 20 bases from the baboon sequence. The corresponding baboon antisense oligonucleotide ISIS 12959, however, was markedly more effective to inhibit c-raf mRNA, protein production, and DNA synthesis, and the results attest to the species specificity of the approach. After antisense treatment, c-raf mRNA levels dropped rapidly, whereas protein levels decreased with a half-life of roughly 24-48 hours, consistent with the antiproliferative effects. The data are discussed with regard to the profile of protein-protein interactions made by C-Raf and with the view that the baboon system closely parallels the human one at the signal transduction level. As this work progressed, a baboon cDNA homolog of a human c-raf-2 pseudogene was isolated, sequenced, and shown to be transcribed into mRNA.     

Newly established causes of diarrhea: the protozoan Cyclospora cayetanensis (Coccidia, Apicomplexa)]

Coccidia Cyclospora cavetanesis has been considered a saprophytic or accidental infection without special medical significance until 1984. However, epidemics of diarrhea first in Peru and later in USA. Haiti and Nepal have aroused interest in pathogenic characteristics of this parasite and diseases it causes. The study first deals with biological cycle of parasite development as well as clinical picture and treatment, diagnostics and epidemiology of this parasitic disease. Clinical picture: On average the incubation period was 2-11 days with frequent stools (3 or more times a day) without blood or mucus and with tendency for recurrence. The prodromal phase is similar to influenza. It may last several weeks especially in immunodeficient persons (especially patients with AIDS). Trimethoprim (160 mg) and sulfamethoxazole (800 mg) is the treatment of choice, twice a day during a 7 day period, whereas in immunodeficient patients greater doses are necessary during a few weeks, but in such cases individual treatment planning is required. Laboratory diagnosis is made on the basis of microscopic examination of native preparation from the stool, especially if stool concentration procedure is used due to small number of oocysts in the stool. As this method does not provide identification of species, numerous staining methods are recommended (modified Ziehl-Neelsen method, Carbol-Fuchsin and safranine). Epidemiology is still unclear. It is considered that there are two sources of infection: contaminated drinking water and fruits. The disease has a seasonal character and the highest incidence is recorded in late spring and summer months. The infection is caused only by sporozoites developed by sporulation of oocysts under environmental conditions excluding the possibility of direct transmission from one person to another. It is to be expected that further investigations will give answers to numerous questions still open.     

Microsporidia of the genus Trachipleistophora--causative agents of human microsporidiosis: description of Trachipleistophora anthropophthera n. sp. (Protozoa: Microsporidia)

Only limited data are available on chromosomes specifically involved in prostatic tumour progression. This study has evaluated the cytogenetic status of primary prostatic carcinomas, local tumour recurrences, and distant metastases, representing different time points in prostatic tumour progression. Interphase in situ hybridization (ISH) was applied with a set of (peri) centromeric DNA probes, specific for chromosomes 1, 7, 8 and Y, to routinely processed tissue sections of 73 tumour specimens from 32 patients. Longitudinal evaluation was possible in 11 cases with local recurrence and nine cases with distant metastases. The remaining 12 patients showed no evidence of local recurrence or distant metastasis after radical prostatectomy on follow-up (mean 60.5 months) and served as a reference. Numerical aberrations of at least one chromosome were found in 27 per cent of the local recurrences and 56 per cent of the distant metastases. In decreasing order of frequency, +8, +7, and -Y were observed in the recurrences and +8, +7, -Y, and +1 in the distant metastases. Evaluation of the corresponding primary tumour tissue of the recurrence group showed numerical aberrations in 45 per cent of cases. The aberrations found were, in decreasing order of frequency, -Y, +7, and +8. In the concomitant primary tumour tissue of the distant metastasis group, numerical aberrations were detected in 67 per cent of cases. The aberrations most frequently encountered were +8, -Y, followed by +7. In four cases, a concordance was found between the primary tumour and its recurrence or distant metastasis. Discrepancies might have been caused by cytogenetic heterogeneity. Comparison of the primary tumour tissue of the reference, the recurrence, and the distant metastasis groups showed a significant increase for the percentage of cases with numerical aberrations (Ptrend = 0.02). Likewise, a trend was seen for gain of chromosome 7 and/or 8 (Ptrend < 0.05). The number of DNA aneuploid tumours also increased in these different groups (Ptrend = 0.03). These data suggest that cancers which recur in time display an intermediate position between tumours of disease-free patients and metastatic cancers.     

The relative electrophoretic mobility of apo(a) isoforms depends on the gel system: proposal of a nomenclature for apo(a) phenotypes

The National Eye Institute (NEI) computer planimetry system has been shown to have good reproducibility in assessing the size of cortical cataracts from retroilluminatin photographs. In this study, we determined the usefulness of this system in monitoring cortical cataract changes over time. Using the Neitz Kawara retroillumination camera, retroillumination photographs of cortical cataracts in 81 eyes were obtained every six months for an average of 31 months. As previously described, the cortical cataract outlines were traced in a masked fashion onto transparent plastic overlays, and the tracings then digitized into a Macintosh Quadra computer using a computer scanner. Cortical cataract area was then determined using a specially developed software program. For each eye, the rate of cortical area change was determined by the slope of the regression line fitted to the follow-up measurements. Cataract progression was classified to be significant if the slope exceeded a critical value. Of the 81 eyes, 24 (30%) had significant cataract progression, while 57 (70%) did not progress. This study presents data on progression of the area of cortical cataracts and suggests the usefulness of the NEI computer planimetry system for monitoring such changes from retroillumination photographs. The slope-based test can also play a useful part in longitudinal studies with irregular time intervals and variable number of visits.     

Isolation and characterization of cDNA clones encoding a 32-kDa dense-granule antigen of Sarcocystis muris (Apicomplexa)

BACKGROUND AND STUDY AIMS: A second-look endoscopy is often performed to evaluate the efficacy of a prior injection therapy in patients with bleeding peptic gastric or duodenal ulcers. Although this strategy is widely established, it does not rely on unequivocal data from controlled studies. In a prospective, randomized, controlled multicenter trial we assessed the effect of programmed endoscopic follow-up examinations with eventual retreatment on the outcome of bleeding ulcers in these patients. PATIENTS AND METHODS: One hundred and five patients with gastric or duodenal peptic ulcers presenting with active (Forrest type I) or recent (Forrest type IIa and IIb) bleeding upon endoscopy within four hours after admission were included in the study. Emergency treatment consisted of the sequential injection of both epinephrine (1:10,000 v/v) and up to 2 ml of fibrin/thrombin around the ulcer base. Fifty-two patients were randomized to receive programmed endoscopic monitoring with eventual retreatment in cases of Forrest type I, IIa, or IIb ulcers beginning within 16-24 hours after the index bleed. Follow-up endoscopies were continued until the macroscopic appearance revealed a Forrest type IIc or III ulcer. Fifty-three patients in the control group were closely monitored, and only received a second endoscopy when there was clinical or biochemical evidence of recurrent bleeding. The groups did not differ with respect to age, sex, site and severity of bleeding. RESULTS: The numbers of patients with recurrent bleeding were similar whether they were endoscopically monitored or not (21% versus 17%, P=0.80 chi-squared test). In addition, there was no statistically significant difference between the two groups with respect to the number of blood units transfused, need for surgical intervention, hospital stay or number of deaths (Mann-Whitney U-test). Improving local ulcer stigmata was not related to a better outcome. CONCLUSIONS: Programmed endoscopic follow-up examinations with eventual retreatment in patients locally injected for an acute or recent hemorrhage from a gastric or duodenal ulcer did not influence their outcome when compared to patients receiving only a second endoscopic intervention upon evidence for recurrent hemorrhage. Scheduled control endoscopies cannot be recommended after an initial successful endoscopic treatment of peptic ulcer bleeding when selection of the patients for second-look endoscopy is directed by the Forrest criteria.