Biology of the schizont - Revision history

Admin at 09:22, 20 March 2025

2025-03-20T09:22:41Z

← Older revision		Revision as of 10:22, 20 March 2025
Line 86:		Line 86:

	<span style="font-size:90%">The release of merozoites from schizonts exposes the body to large amounts of free parasite antigens no longer contained within the erythrocytes - the result is an immune response causing high fever and illness symptoms. In some cases the development of parasites is synchronous so that all schizonts mature and release their merozoites at the same time - although rarely seen now, this pattern of development may produce a pattern of remitting fever with a distinct periodicity depending on species: underlying the older descriptive terms tertian or quartan malaria.</span>		<span style="font-size:90%">The release of merozoites from schizonts exposes the body to large amounts of free parasite antigens no longer contained within the erythrocytes - the result is an immune response causing high fever and illness symptoms. In some cases the development of parasites is synchronous so that all schizonts mature and release their merozoites at the same time - although rarely seen now, this pattern of development may produce a pattern of remitting fever with a distinct periodicity depending on species: underlying the older descriptive terms tertian or quartan malaria.</span>
			</br>
	~~----~~

Admin at 09:22, 20 March 2025

2025-03-20T09:22:16Z

← Older revision		Revision as of 10:22, 20 March 2025
Line 76:		Line 76:


	<span style="font-size:90%">Merozoites cause the red cell membrane to be expanded then to break down; the merozoites (M) are now clearly separate and move apart, the pigment (P) is also released during this process ~~(A)~~; this is shown in the clinical image (B) although this brief stage is rarely seen in practice (''P.malariae'').</span>		<span style="font-size:90%">Merozoites cause the red cell membrane to be expanded then to break down. Image A: the merozoites (M) are now clearly separate and move apart, the pigment (P) is also released during this process; this is also shown in the clinical image (B) although this brief stage is rarely seen in practice (''P.malariae'').</span>

	----		----

Admin at 09:20, 20 March 2025

2025-03-20T09:20:51Z

← Older revision		Revision as of 10:20, 20 March 2025
Line 65:		Line 65:


	<span style="font-size:90%">The asexual division cycles are now complete ~~cartoon image (~~A) shows the merozoites (M) as discrete chromatin with blue cytoplasm. Malaria pigment is present (P). The clinical image of a parasite at this developmental stage (again from ''P.ovale'' with well shown James'dots and malaria pigment) is shown in panel (B).</span>		<span style="font-size:90%">The asexual division cycles are now complete. Image A shows the merozoites (M) as discrete chromatin with blue cytoplasm. Malaria pigment is present (P). The clinical image of a parasite at this developmental stage (again from ''P.ovale'' with well shown James'dots and malaria pigment) is shown in panel B.</span>

Admin at 09:19, 20 March 2025

2025-03-20T09:19:33Z

← Older revision		Revision as of 10:19, 20 March 2025
Line 53:		Line 53:
	</gallery>		</gallery>

	<span style="font-size:90%">The ~~cartoon~~ image (A) shows the further division of chromatin (Chr) into many discrete massed within the blue parasite cytoplasm (Cy). Individual merozoites are still not distinguishable but the malaria pigment is obvious (Pi). A clinical image of a parasite at this developmental stage (again from ''P.ovale'' with well shown James'dots and malaria pigment) is shown in panel (B).</span>		<span style="font-size:90%">The diagramatic image (A) shows the further division of chromatin (Chr) into many discrete massed within the blue parasite cytoplasm (Cy). Individual merozoites are still not distinguishable but the malaria pigment is obvious (Pi). A clinical image of a parasite at this developmental stage (again from ''P.ovale'' with well shown James'dots and malaria pigment) is shown in panel (B).</span>

Admin at 09:18, 20 March 2025

2025-03-20T09:18:33Z

← Older revision		Revision as of 10:18, 20 March 2025
Line 42:		Line 42:
	</gallery>		</gallery>

	<span style="font-size:90%">The ~~cartoon~~ image (A) shows the division of chromatin into two distinct purple chromatin masses within the blue parasite cytoplasm (at this point the cytoplams is not divided so indiviual merozoites are not really distinguishable). A clinical image of a parasite at this developmental stage (''P.ovale'' with well shown James'dots) is shown in panel (B).</span>		<span style="font-size:90%">The diagramatic image (A) shows the division of chromatin into two distinct purple chromatin masses within the blue parasite cytoplasm (at this point the cytoplams is not divided so indiviual merozoites are not really distinguishable). A clinical image of a parasite at this developmental stage (''P.ovale'' with well shown James'dots) is shown in panel (B).</span>

Admin at 10:04, 17 March 2025

2025-03-17T10:04:31Z

← Older revision		Revision as of 11:04, 17 March 2025
Line 31:		Line 31:
	<span style="font-size:90%">(1) The number of replication cycles differs between species: the typical number of merozoites formed differs between species with as few as 8 (in ''P.malariae'') up to a possible 32 (in ''P.vivax'')</br>(2) This stage may not always be seen in blood: the schizonts of ''P.falciparum'' adhere within the small vessels so is not seen in blood unless infection is very severe		<span style="font-size:90%">(1) The number of replication cycles differs between species: the typical number of merozoites formed differs between species with as few as 8 (in ''P.malariae'') up to a possible 32 (in ''P.vivax'')</br>(2) This stage may not always be seen in blood: the schizonts of ''P.falciparum'' adhere within the small vessels so is not seen in blood unless infection is very severe
	</br></br></span>		</br></br></span>
	<span style="font-size:90%">Schizonts formation involves successive cycles of asexual division that eventually result in the formation of multiple separate "merozoite" forms. Those merozoites are released as the red cell breaks down then go on to infect another red cell. Schizonts ~~therefre~~ look very different depending on which stage of development they represent. The progressive maturation of this parasite stage means that they have a wide range of morphological forms. However, these can be readily recognised on blood films by reference to their biology (see below).</br>		<span style="font-size:90%">Schizonts formation involves successive cycles of asexual division that eventually result in the formation of multiple separate "merozoite" forms. Those merozoites are released as the red cell breaks down then go on to infect another red cell. Schizonts therefore look very different depending on which stage of development they represent. The progressive maturation of this parasite stage means that they have a wide range of morphological forms. However, these can be readily recognised on blood films by reference to their biology (see below).</br>


Line 45:		Line 45:


	<span style="font-size:90%">'''Immature schizonts'''</br>As schizont development proceeds further cycles of division cause the appearance of mutiple separate areas chromatin that will eventually form the ~~merozoies~~, although at this stage they still lie within a single cytoplasmic mass. The number of divisions varies between species, so in mature schizonts this can contribute to species identification (see schizont gallery). Note that as the parasites develop the haemoglobin is metabolised so the red cell becomes more pale, and the products of red cell breakdown (malaria pigment) become more prominent.</span>		<span style="font-size:90%">'''Immature schizonts'''</br>As schizont development proceeds further cycles of division cause the appearance of mutiple separate areas chromatin that will eventually form the merozoites, although at this stage they still lie within a single cytoplasmic mass. The number of divisions varies between species, so in mature schizonts this can contribute to species identification (see schizont gallery). Note that as the parasites develop the haemoglobin is metabolised so the red cell becomes more pale, and the products of red cell breakdown (malaria pigment) become more prominent.</span>


Line 53:		Line 53:
	</gallery>		</gallery>

	<span style="font-size:90%">The cartoon image (A) shows the further division of chromatin (Chr) into many discrete massed within the blue parasite cytoplasm (Cy). ~~Indiviual~~ merozoites are still not distinguishable but the malaria pigment is obvious (Pi). A clinical image of a parasite at this developmental stage (again from ''P.ovale'' with well shown James'dots and malaria pigment) is shown in panel (B).</span>		<span style="font-size:90%">The cartoon image (A) shows the further division of chromatin (Chr) into many discrete massed within the blue parasite cytoplasm (Cy). Individual merozoites are still not distinguishable but the malaria pigment is obvious (Pi). A clinical image of a parasite at this developmental stage (again from ''P.ovale'' with well shown James'dots and malaria pigment) is shown in panel (B).</span>


Line 68:		Line 68:


	<span style="font-size:90%">'''Merozoite release'''</br></br>In the final stage the red cell membrane is broken down, swelling then separating to release the merozoites and any malaria pigment into the blood where each merozoite enters a red cell to form a new early trophozoite and increasing the infection load. This process also results in the release of malaria pigment which my be [[Phagocytosis of malaria pigment b\|taken up by phagocytes]] and detected on ~~bllod~~ films.</span>		<span style="font-size:90%">'''Merozoite release'''</br></br>In the final stage the red cell membrane is broken down, swelling then separating to release the merozoites and any malaria pigment into the blood where each merozoite enters a red cell to form a new early trophozoite and increasing the infection load. This process also results in the release of malaria pigment which my be [[Phagocytosis of malaria pigment b\|taken up by phagocytes]] and detected on blood films.</span>

	<gallery mode="nolines" widths="180px" heights="180px" >		<gallery mode="nolines" widths="180px" heights="180px" >

Admin at 17:43, 20 February 2025

2025-02-20T17:43:29Z

← Older revision		Revision as of 18:43, 20 February 2025
Line 68:		Line 68:


	<span style="font-size:90%">'''Merozoite release'''</br></br>In the final stage the red cell membrane is broken down, swelling then separating to release the merozoites and any malaria pigment into the blood where each merozoite enters a red cell to form a new early trophozoite and increasing the infection load. This process also results in the release of malaria pigment which my be [[~~taken up by phagocytes\|~~Phagocytosis of malaria pigment-b]] and detected on bllod films.</span>		<span style="font-size:90%">'''Merozoite release'''</br></br>In the final stage the red cell membrane is broken down, swelling then separating to release the merozoites and any malaria pigment into the blood where each merozoite enters a red cell to form a new early trophozoite and increasing the infection load. This process also results in the release of malaria pigment which my be [[Phagocytosis of malaria pigment b\|taken up by phagocytes]] and detected on bllod films.</span>

	<gallery mode="nolines" widths="180px" heights="180px" >		<gallery mode="nolines" widths="180px" heights="180px" >

Admin at 17:42, 20 February 2025

2025-02-20T17:42:41Z

← Older revision		Revision as of 18:42, 20 February 2025
Line 68:		Line 68:


	<span style="font-size:90%">'''Merozoite release'''</br></br>In the final stage the red cell membrane is broken down, swelling then separating to release the merozoites and any malaria pigment into the blood where each merozoite enters a red cell to form a new early trophozoite and increasing the infection load. This process also results in the release of [[malaria pigment which my be taken up by phagocytes]] and detected on bllod films.</span>		<span style="font-size:90%">'''Merozoite release'''</br></br>In the final stage the red cell membrane is broken down, swelling then separating to release the merozoites and any malaria pigment into the blood where each merozoite enters a red cell to form a new early trophozoite and increasing the infection load. This process also results in the release of malaria pigment which my be [[taken up by phagocytes\|Phagocytosis of malaria pigment-b]] and detected on bllod films.</span>

	<gallery mode="nolines" widths="180px" heights="180px" >		<gallery mode="nolines" widths="180px" heights="180px" >

Admin at 17:41, 20 February 2025

2025-02-20T17:41:16Z

← Older revision		Revision as of 18:41, 20 February 2025
Line 68:		Line 68:


	<span style="font-size:90%">'''Merozoite release'''</br></br>In the final stage the red cell membrane is broken down, swelling then separating to release the merozoites and any malaria pigment into the blood where each merozoite enters a red cell to form a new early trophozoite and increasing the infection load.</span>		<span style="font-size:90%">'''Merozoite release'''</br></br>In the final stage the red cell membrane is broken down, swelling then separating to release the merozoites and any malaria pigment into the blood where each merozoite enters a red cell to form a new early trophozoite and increasing the infection load. This process also results in the release of [[malaria pigment which my be taken up by phagocytes]] and detected on bllod films.</span>

	<gallery mode="nolines" widths="180px" heights="180px" >		<gallery mode="nolines" widths="180px" heights="180px" >

Admin at 18:33, 30 November 2024

2024-11-30T18:33:39Z

← Older revision		Revision as of 19:33, 30 November 2024
Line 31:		Line 31:
	<span style="font-size:90%">(1) The number of replication cycles differs between species: the typical number of merozoites formed differs between species with as few as 8 (in ''P.malariae'') up to a possible 32 (in ''P.vivax'')</br>(2) This stage may not always be seen in blood: the schizonts of ''P.falciparum'' adhere within the small vessels so is not seen in blood unless infection is very severe		<span style="font-size:90%">(1) The number of replication cycles differs between species: the typical number of merozoites formed differs between species with as few as 8 (in ''P.malariae'') up to a possible 32 (in ''P.vivax'')</br>(2) This stage may not always be seen in blood: the schizonts of ''P.falciparum'' adhere within the small vessels so is not seen in blood unless infection is very severe
	</br></br></span>		</br></br></span>
	<span style="font-size:90%">Schizonts formation involves successive cycles of asexual division that eventually result in the formation of multiple separate "merozoite" forms. Those merozoites are released as the red cell breaks down then go on to infect another red cell. Schizonts therefre look very different depending on which stage of development they represent. ~~Below are images~~ of ~~schizonts at different developmental stages~~.</~~span~~>		<span style="font-size:90%">Schizonts formation involves successive cycles of asexual division that eventually result in the formation of multiple separate "merozoite" forms. Those merozoites are released as the red cell breaks down then go on to infect another red cell. Schizonts therefre look very different depending on which stage of development they represent. The progressive maturation of this parasite stage means that they have a wide range of morphological forms. However, these can be readily recognised on blood films by reference to their biology (see below).</br>


	~~----~~

	<span style="font-size:90%">'''Initial asexual replication'''</br>The first recognisable stage occurs when the schizonts first divide their chromatin to form two distinct masses. This first stage is the least distinctive and can be difficult to distinguish from a late trophozoite or gametocyte with a double chromatin dot. But often the appearance is clear.</span>		<span style="font-size:90%">'''Initial asexual replication'''</br>The first recognisable stage occurs when the schizonts first divide their chromatin to form two distinct masses. This first stage is the least distinctive and can be difficult to distinguish from a late trophozoite or gametocyte with a double chromatin dot. But often the appearance is clear.</span>
Line 50:		Line 48:


	<gallery mode="nolines" widths="~~200px~~" heights="~~220px~~" >		<gallery mode="nolines" widths="180px" heights="180px" >
	File:Schizontcartoon2.jpg\|A\|link={{filepath:Schizontcartoon2.jpg}}		File:Schizontcartoon2.jpg\|A\|link={{filepath:Schizontcartoon2.jpg}}
	File:Schizontreal2.jpg\|B\|link={{filepath:Schizontreal2.jpg}}		File:Schizontreal2.jpg\|B\|link={{filepath:Schizontreal2.jpg}}
Line 58:		Line 56:


	-~~---~~		<span style="font-size:90%">'''Mature schizonts'''</br></br>By this stage the individual merozoites can be distinguished, each with a chromatin dot and cytoplasm; they are now ready for release from the red cell.</span>

	<span style="font-size:90%">'''MATURE SCHIZONT APPEARANCES'''</br></br>By this stage the individual merozoites can be distinguished, each with a chromatin dot and cytoplasm; they are now ready for release from the red cell.</span>

			<gallery mode="nolines" widths="180px" heights="180px" >
	<gallery mode="nolines" widths="~~200px~~" heights="~~220px~~" >
	File:Schizontcartoon3.jpg\|A\|link={{filepath:Schizontcartoon3.jpg}}		File:Schizontcartoon3.jpg\|A\|link={{filepath:Schizontcartoon3.jpg}}
	File:Schizontreal3.jpg\|B\|link={{filepath:Schizontreal3.jpg}}		File:Schizontreal3.jpg\|B\|link={{filepath:Schizontreal3.jpg}}
Line 72:		Line 68:


	-~~---~~		<span style="font-size:90%">'''Merozoite release'''</br></br>In the final stage the red cell membrane is broken down, swelling then separating to release the merozoites and any malaria pigment into the blood where each merozoite enters a red cell to form a new early trophozoite and increasing the infection load.</span>

			<gallery mode="nolines" widths="180px" heights="180px" >
	<span style="font-size:90%">'''MEROZOITE RELEASE'''</br></br>In the final stage the red cell membrane is broken down, swelling then separating to release the merozoites and any malaria pigment into the blood where each merozoite enters a red cell to form a new early trophozoite and increasing the infection load.</span>

	<gallery mode="nolines" widths="~~200px~~" heights="~~220px~~" >
	File:Schizontcartoon4.jpg\|A\|link={{filepath:Schizontcartoon4.jpg}}		File:Schizontcartoon4.jpg\|A\|link={{filepath:Schizontcartoon4.jpg}}
	File:Schizontreal4.jpg\|B\|link={{filepath:Schizontreal4.jpg}}		File:Schizontreal4.jpg\|B\|link={{filepath:Schizontreal4.jpg}}
Line 84:		Line 77:

	<span style="font-size:90%">Merozoites cause the red cell membrane to be expanded then to break down; the merozoites (M) are now clearly separate and move apart, the pigment (P) is also released during this process (A); this is shown in the clinical image (B) although this brief stage is rarely seen in practice (''P.malariae'').</span>		<span style="font-size:90%">Merozoites cause the red cell membrane to be expanded then to break down; the merozoites (M) are now clearly separate and move apart, the pigment (P) is also released during this process (A); this is shown in the clinical image (B) although this brief stage is rarely seen in practice (''P.malariae'').</span>


	<span style="font-size:90%">The progressive maturation of this parasite stage means that they have a wide range of morphological forms. However, these can be readily recognised on blood films by reference to their biology.</br></br>[ [[Images of schizont morphology\|See clinical images illustrating schizont development]] ]</span>

	----		----