Synchronicity Index: Difference between revisions
From MalariaETC
No edit summary |
No edit summary |
||
| Line 12: | Line 12: | ||
<span style="font-size:90%>In some malaria infections (particularly with ''P.falciparum'' or with ''P.knowlesi'') there may be only a single parasite stage visible in blood – this is most often the early trophozoite stage. This process is partly a reflection of the interesting phenomenon of “synchronicity” of parasite development.</br></br></span> | <span style="font-size:90%>In some malaria infections (particularly with ''P.falciparum'' or with ''P.knowlesi'') there may be only a single parasite stage visible in blood – this is most often the early trophozoite stage. This process is partly a reflection of the interesting phenomenon of “synchronicity” of parasite development.</br></br></span> | ||
<gallery mode="nolines" widths="220px" heights="220px" > | <gallery mode="nolines" widths="220px" heights="220px" > | ||
File: | File:PFET_synchronous.jpg|link={{filepath:PFET_synchronous.jpg}} | ||
</gallery> | </gallery> | ||
<span style="font-size:90%>While the precise reasons and mechanisms of synchronicity are not fully clear, the biological effects can be clearly seen in some cases where the stages of invasion of erythrocytes, their asexual replication, then their escape from schizonts each occur in unison. The process appears to reflect the normal circadian rhythms of host hormones, with changes seen to affect both in gene expression and parasite behaviour. This synchronicity results in parasites in blood reflecting only a single stage. </br></br></span> | <span style="font-size:90%>While the precise reasons and mechanisms of synchronicity are not fully clear, the biological effects can be clearly seen in some cases where the stages of invasion of erythrocytes, their asexual replication, then their escape from schizonts each occur in unison. The process appears to reflect the normal circadian rhythms of host hormones, with changes seen to affect both in gene expression and parasite behaviour. This synchronicity results in parasites in blood reflecting only a single stage. </br></br></span> | ||
<span style="font-size:90%>It is thought that the fevers in malaria are caused by the sudden antigen load that occurs during schizont release</br></br></span> | <span style="font-size:90%>It is thought that the fevers in malaria are caused by the sudden antigen load that occurs during schizont release</br></br></span> | ||
<gallery mode="nolines" widths="220px" heights="220px" > | <gallery mode="nolines" widths="220px" heights="220px" > | ||
File: | File:Schizont_release.jpg|link={{filepath:Schizont_release.jpg}} | ||
</gallery> | </gallery> | ||
<span style="font-size:90%>Therefore, when schizont release is synchronous it can lead to the recognised phenomena of periodic fevers: e.g. in ''P.falciparum'' infection untreated individuals may exhibit fever cycles,with a 48-hour cycle so the periodicity corresponding to periods of abrupt schizont release (“tertian malaria”). This is not absolute with some infections appearing synchronous and others not.</span> | <span style="font-size:90%>Therefore, when schizont release is synchronous it can lead to the recognised phenomena of periodic fevers: e.g. in ''P.falciparum'' infection untreated individuals may exhibit fever cycles,with a 48-hour cycle so the periodicity corresponding to periods of abrupt schizont release (“tertian malaria”). This is not absolute with some infections appearing synchronous and others not.</span> | ||
Revision as of 17:45, 5 December 2024
| Synchronour development of parasites
In some malaria infections (particularly with P.falciparum or with P.knowlesi) there may be only a single parasite stage visible in blood – this is most often the early trophozoite stage. This process is partly a reflection of the interesting phenomenon of “synchronicity” of parasite development. While the precise reasons and mechanisms of synchronicity are not fully clear, the biological effects can be clearly seen in some cases where the stages of invasion of erythrocytes, their asexual replication, then their escape from schizonts each occur in unison. The process appears to reflect the normal circadian rhythms of host hormones, with changes seen to affect both in gene expression and parasite behaviour. This synchronicity results in parasites in blood reflecting only a single stage. Therefore, when schizont release is synchronous it can lead to the recognised phenomena of periodic fevers: e.g. in P.falciparum infection untreated individuals may exhibit fever cycles,with a 48-hour cycle so the periodicity corresponding to periods of abrupt schizont release (“tertian malaria”). This is not absolute with some infections appearing synchronous and others not. |
