Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

intro to biomedical sciences IBMS > Proteopathic diseases and amelogensis imperfecta II > Flashcards

Proteopathic diseases and amelogensis imperfecta II Flashcards

1
Q

what is amelogensis imperfecta

A

a group of developmental conditions that are genomic in origin which affects the structure and appearance of the enamel and nearly all of the enamel in every tooth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the prevalence of AI

A

1 in 700- 1 in 1400 depending on population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how can AI also be present

A

in cone rod dystrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

in geneitcs how can AI be acquired

A

autosomal dominant
autosomal recessive
sex linked
and shows sporadic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

phenotypes of AI

A

hyperplastic- pitting of enamel with an open bite
hypermineralised- rough soft enamel which is discoloured
hypermaturation- enamel normal thickness and very whiteish surface- can be mistaken as fluorosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is present in all cases of AI

A

in all cases teeth are sensitive, discoloured and prone to disintegration by post eruptive breakdown and idiopathic resorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the key features of hyperplasia

A

pitting of enamel with open bite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the Key features of hyper-mineralisation

A

rough soft enamel which is discoloured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the Key features of hyper-maturation

A

normal thickness of enamel, whiteish enamel can be frequently mistaken for fluorosis
sensitive teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

mutations in which genes are responsible for AI

A

amelogenin and enamelin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the wild type phenotype in mice

A

allele codes for phenotype most commonly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what has the Riken institute in Japan developed

A

a mass mutogenic library of mice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how have the Riken institute made this library

A

done this by feeding male mice ENUand this causes them to form point mutation and then interbreed with normal mice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is ENU

A

ENU(N-ethyl-N-nitroso urea)- A HIGHLY POTENT MUTAGEN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how many dentitions do mice have

A

monophyodont dentition- only one permanent set of dentition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the mouse incisor characterised by on SEM

A

A herring-bow pattern with different levels of complexity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what allows the incisor to remain chiselled and sharp

A

the columnar and laminar structure of the HAP crystals which form rods with interods in between

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the enamel characterised by

A

characterised by C axis hydroxyl ion where the Ca and Phosphate arrange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the enamel formation stages based on

A

tissue structure
histology of the adjacent enamel organ cells
enamel chemistry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what two stages are easily found

A

secretion stage

maturation stage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the characteristics of the secretion stage

A

characterised by:
secretion of matrix and the initial mineral phase and is complete when the full thickness of this complete tissue is deposited.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are characteristics of the maturation stage

A

characterise by:
final matrix is removed and the final mineral content is acquired
complete when post eruption phase when it is not mediated by cells of the enamel organ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what stage is also included in the literature

A

transition phase( early maturation phase) between secretory and maturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

when does the transition phase occur

A

when the amelogenin is secreted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how are the phases concerned

A

as discrete

26
Q

what are the characteristics of the early maturation phase

A

the ameloblasts are long and columnar and around 7 microns in length
the ER is also denser

27
Q

what happens to the ameloblasts as the matrix is deposited in the maturation phase

A

the height of the ameloblasts decreases to around 3.5 microns in length
the ER is less dense
nucleus is also more in the centre of the cell

28
Q

what is the mineral content in the secretion stage

A

around 30%

29
Q

what is the mineral content in the early maturation stage

A

around 40%

30
Q

what is the mineral content in the in the maturation stage

A

around 90%

31
Q

what minerals increase in amount in the maturation stage

A

calcium and phosphate

32
Q

what happens in the secretory stage

A

enamel proteins are secreted

33
Q

what happens in the early maturation stage

A

enamel proteins stop being secreted

34
Q

what happens in the maturation stage

A

proteins are removed and replaced by enamel

35
Q

what is the enamel matrix mainly composed of

A

around 90% amelogenin

36
Q

where is amelogenin found in chromosomes in humans

A

on the x chromosomes and Y

37
Q

where is amelogenin found in chromosomes in rodents

A

on the x chromosome

38
Q

if you have a heterozygous female rodent that reproduces what are the chances of getting AI

A

50% affected

50% unaffacted

39
Q

if you have affected male rodent that reproduces what are the chances of getting AI

A

100% affected

40
Q

what does the enamel look like in 100% affected offspring from XY affected males

A

no enamel is formed just a thin layer of descript material on top of the dentine

41
Q

what does the enamel look like in 50% affected offspring from XX affected female

A

enamel is formed but it is just abnormal

42
Q

what is lyonisation

A

where one copy of the x chromosome is turned off- gives rise to banded enamel in HETEROZYGOUS females with X LINKED AI

43
Q

What does the histology of the enamel look like in heterozygous amelogenin mutant females

A

we can see strong eosinophilic vesicles in the enamel of the ameloblasts
more vascular in nature
herring-bow structure of the tomes process is lost

44
Q

what are the eosinophilic vesicles packed with

A

amelogenin and ameloblastin- the proteins co localised within the vesicles

45
Q

where does the failure lie if mutant amelogenin is accumulating in the ameloblasts

A

in the secretory pathway

46
Q

what accumulates in the ameloblasts

A

mutant amelogenin due to an error in the secretory pathway

47
Q

what does amelogenin mutation cause

A

loss of normal ER and golgi structure and the ameloblasts become engorged and filled with amelogenin filled vesicles

48
Q

what causes ER stress

A

mutant amelogenin buildup which leads to activation o the unfolded protein response

49
Q

what does the upr end up causing

A

attempts to restore proteostasis but will tip towards apoptosis with increasing time and stress

50
Q

what chemical is used also as a chaperone

A

phenylbuterate which can act as a chaperone and help to refold chemical misfoldings

51
Q

what drug can be used to treat urea cycle disorders

A

phenylbuterate

52
Q

what is phenylbuterate used to treat

A

urea cycle disorders

53
Q

how can phenylbuterate help mince

A

the visual shoring showed a marked improvement on the incisors but not on the molars

54
Q

what is the mechanism of AI recovery by phenylbuterate

A

the phenylbuterate chaperones the proteins and mitigates the stress leading to ameloblasts not dying and the monolayer is retained allowing for healthy enamel to form

55
Q

how long does it take for the UPR to switch from survival mode to death mode

A

around 6 days- thats when cells undergo apoptosis

56
Q

what do mice with the enamelin mutation( S55I) show

A

massive defects in the enamel

less mineral density along the incisor

57
Q

what is shown in the heterozygous S55I mutation in mice in regards to mineral content

A

good mineral content around the incisal edge but poor at the beginning

58
Q

what is shown in the heterozygous S55I mutation in mice in regards to mineral content

A

poor all along

and poor enamel all along

59
Q

is there a statically difference in the fold change of ENAM HETERO AND ENAM HOMO in BIP

A

no statisical difference

60
Q

is there a statically difference in the fold change of ENAM HETERO AND ENAM HOMO in CHOP

A

statistical difference

61
Q

what does the mutation in ENAM S55I show

A

that it inhibits the ameloblasts secondary pathway and leading to ER stress and the UPR which leads to slight recovery and the deposition of normal enamel but the enamel secreted after was abnormal

62
Q

what can fluoride trigger

A

an unfolded protein response which could trigger ameloblast function and or survival and lead to fluorotic enamel defects causing fluorosis
it doesnt cause protein misfolding just activates in some way

intro to biomedical sciences IBMS (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions