Cryptic stage of sleeping-sickness trypanosome developing in choroid plexus epithelial cells.

Abstract

further radioactive substance being given, emission computed tomography of the kidneys was then performed using the same gamma camera connected to an image analysis computer (Gamma-il, Digital Equipment Go) in its rotation mode. Data were collected for 20 s at each of 64 views equally spaced through 360. around the patient. Sagittal sections were then computed (fig 2d,e), which clearly showed that in the left kidney the functioning cortical tissue extended across the middle of the kidney. The radiographs were then reviewed and another ultrasound investigation done, after which it was concluded that the left kidney showed partial reduplication of the collecting system with interposed solid tissue having the characteristics of normal renal parenchyma. The renal abnormality was therefore a hypertrophied column of Bertin. DiscussionThe column of Bertin may be a source of considerable confusion in radiographic investigation of the kidney since it may simulate a renal tumour on an excretion urogram and may require angiography for diagnosis.4 Ultrasonography may be unhelpful, not only if the patient yields poor-quality images owing to, for example, obesity but also because the calyceal appearance in healthy kidneys varies considerably and a small amount of distortion is therefore easily missed. Conventional radionuclide images may also, as in this case, be unhelpful. The usual procedure to determine the nature of the suspected lesion would then be to proceed to selective renal angiography.4 In this case the necessity for this invasive investigation of a healthy kidney was obviated by the clear tomographic radionuclide images obtained. In other patients we have found that emission tomographic imaging of the kidney can be a useful adjunct to other non-invasive studies.5We are grateful to Dr P G Rose, consultant radiologist, for his advice and opinion on this case. Progressive degeneration of the ependymal cell liberates trypomastigotes back into the perivascular space, from which re-entry into the blood may occur. Re-entry to the blood does not take place from any tissues other than the brain and its membranes. References

Histopathology of Trypanosoma (Trypanozoon) evansi infection in Bandicoot rat. II. Brain and choroid plexus

“…Fatty degeneration of the brain tissue of 14day pi bandicoot is seen. × 85. cryptic stage of sleeping sickness trypanosome develops within the ependymal cells of the choroid plexus from where re-entry into the blood may occur (Abolarin et al, 1982(Abolarin et al, , 1986. This is perhaps the first document to show the presence of intracellular stages in brucei group of trypanosome.…”

“…This is perhaps the first document to show the presence of intracellular stages in brucei group of trypanosome. Damage of the choroid plexus is studied in man and animals suffering from sleeping sickness disease Abolarin et al, 1982Abolarin et al, , 1986Ormerod and Hussein, 1986) as well as in minipigs infected with T. brucei (Büngener and Mehlitz, 1984). Such studies are so far not undertaken in animals suffering from surra disease.…”

Immunological function of the blood-cerebrospinal fluid barrier.

“…Because substances present in brain parenchyma are known to enter the CSF, the choroid has potential access to antigens present not only exclusively in the CSF but also arising from elsewhere in the CNS outside the ventricular system (including, e.g., antigens coming from brain parenchymal infections). Our findings also have implications for the recognition of certain systemic viruses, parasites, and other antigens (e.g., lymphocytic choriomeningitis virus and trypanosomes) that may enter the CSF through, or proliferate within, the choroid plexus (27)(28)(29)(30) (31,32), or communication through the endothelial cells of the blood-brain barrier (33,34) or through…”

African Trypanosomes Have Differentially Expressed Genes Encoding Homologues of the Leishmania GP63 Surface Protease

“…Likewise, the expression of GP63 predominantly in bloodstream trypanosomes is counter to what one might expect, based on the detection of GP63s on the surface of the insect-specific protozoa, C. fasciculata and H. samuelpessoai. It is worth mentioning, however, that in experimental infections of rats and mice with Trypanosoma brucei brucei, intracellular parasites have been reported to occur in the epithelium (ependymal cells) that covers the choroid plexus and constitutes the local blood-brain barrier (61)(62)(63). Although, to our knowledge, the existence of an intracellular form of African trypanosomes has not been reconfirmed since the original reports in 1982-1986, this observation might be of significance in considering a potential role for GP63 when the parasite crosses the blood-brain barrier.…”