Review #2 Flashcards
What is pathogenesis?
The mechanism of development of a pathology
What is pathophysiology?
The functional changes associated with or resulting from the disease or injury
What are morphological changes?
Structural alterations in cells or tissues that are characteristic of a disease
What does a holoprosencephaly baby look like?
Cyclops
What teratogens can cause holoprosencephaly?
Alcohol
Retinoic acid
What things can cause holoprosencephaly?
Genetic factors (10-15%) autosomal recessive
Teratogens
Maternal diabetes
Maternal hypocholesterolemia
What signaling is lost in holoprosencephaly?
Anterior pituitary signaling
What is craniostosis?
When the sutures close too early, and pressure of the growing brain pushes out and deforms the head
What are the two types of craniostosis?
Syndromic
Non-syndromic
What are the diseases of syndromic craniostosis?
Pfeiffer
Apert/Crouzon
Saethre-Chotzen
Greig cephalopolysyndactyly
What causes non-syndromic craniostosis?
Compression associated:
- Multiple fetuses
- Uterine malformation
What disease comes from a 3rd and 4th pharyngeal arch disorder?
DiGeorge syndrome
What is absent in DiGeorge syndrome?
Absence of thymus &/or parathyroid
What symptoms are associated with DiGeorge syndrome?
Micrognathia Hypertelorism Low set, angled ears Short philtrum Choanal atresia
What is hypertelorism?
Wide set eyes
What is choanal atresia?
Extra tissu in the nasal passage, causing respiratory problems.
What syndrome/disease is caused by a 1st arch disorder?
Treacher Collins
Treacher Collins is cause by a lack of ___ ___ migration/population
Neural Crest
What is the suspect gene in Treacher Collins?
Tcof1
What is Tcof1?
A transcription factor gene on chromosome 5 - Treacher Collins
What is a colboma?
Eyebrow notch
In what disease/syndrome is a coloboma often seen?
Treacher Collins
What does TORCH stand for? (Teratogens)
Toxoplasmosis Other: HIV, syphillis, VZV (chickenpox) Rubella CMV (cytomegola virus) HSV (herpes simplex)
What are symptoms of Cri du Chat syndrome?
Microcephaly
Micrognathia
Hypertelorism
Severe retardation
What causes Cri du Chat syndrome?
Deletion of 5p gene
Cri du Chat is a partial ___.
Monosomy
What syndrome is trisomy 13?
Patau
What syndrome is trisomy 18?
Edward
What syndrome is trosomy 21?
Down’s
Why aren’t autosomal trisomies found?
They are lethal
What is XXX?
Super female - common abnormal karyotype
What is XO?
Turner’s syndrome
What is the only recognized monosomy?
Turner’s syndrome
What is XXY?
Kleinfelter syndrome
What is XYY?
Super male - common abnormal karyotype
Richard Speck
During which meiosis does a nondisjunction have to occur to yield uniparental disomy?
Meiosis II
What happens in a nondisjunction during meiosis II?
Sister chromatids don’t disjoin and both go to one daughter cell
What are some general characteristics of multifactorial disorders?
Run in families
No single gene
Usually a combination of genetics & environmental factors required for phenotypic expression
Don’t follow Mendelian genetics
What are some examples of multifactorial disorders?
Coronary heart disease IDDM Hypertension Some forms of cancer Developmental defects
What are some multifactorial disorders from developmental defects?
Congenital heart defects
Spina bifida
Anencephaly
Cleft palate
What is an anomaly?
A structural defect of any type
What is a malformation?
Intrinsic; genetic
What is a deformation?
Extrinsic; mechanical
What is a disruption?
Extrinsic; teratogen exposure
What is a syndrome?
Multiple anomalies that occur independently, but are caused by a single defect
What is a sequence?
When a structural or mechanical factor leads to multiple secondary effects
When is a maternal serum screen done?
15-20 weeks of gestation
In an MSS, the result shows hight HCG. What does the baby probably have?
Trisomy 21 - Down’s
An MSS shows high AFP. What does the baby probably have?
Neural tube defects
What trisomies can MSS uncover?
18
21
What does MSS stand for?
Maternal serum screen
What are homologues?
Identical chromosomes originating from different partents
What are sister chromatids?
Duplicated copy of each chromosome following S phase
What connects sister chromatids?
Centromere
What are bivalents or tetrads?
A pair of duplicated homologues - 2 pairs of sister chromatids
When does meiosis begin in males?
At puberty
What is produced from meiosis in males?
4 haploid gametes produces/PGC
When does meiosis begin in females?
In utero
What is produced in female meiosis?
1 haploid gamete produced/PGC
In prophase of meiosis I, oocytes are arrested at ___ stage, until ovulation.
Diplotene
What is the prolonged female diplotene stage called?
Dictyotene
What happens during leptotene?
Chromosomes begin to condense
What happens during zygotene?
Tetrads from between homologues - unique to meiosis
What happens during pachytene?
Homologous recombination occurs
What happens during diplotene?
Bivalents “repel”; chiasmata become evident
What happens during diakinesis?
Chromosomes are maximally condensed
What triggers the proteolytic breakdown of the ovarian wall for ovulation?
LH
The LH surge causes what?
The ovulation of the egg, and completion of meiosis I
LH triggers the breakdown of the ovarian wall, but what actually does the breaking down?
Serine proteases, plasmin, from the granulosa
What inhibits the granulosa-secreted enzymes?
Theca cells
IP3 and CA2+ go through ___ ___ into the oocyte.
Gap junctions
When IP3 & Ca2+ enter the oocyte, what is activated?
PKC
What does PKC target?
C-mos - an oocyte specific kinase
What does C-mos do?
Increases MPF activity
What is MPF?
Maturation promoting factor, which is cyclin B + p34CDK1
What does MPF target?
Nuclear lamins, triggering germinal vesicle breakdown and completion of meiosis I
How long does spermiogenesis take?
About 64 days
How many sperm mature per day?
About 300 million
What builds the acrosomal cap for the sperm?
The Golgi
What is the first step of fertilization?
Sperm binds to the zona pellucida at the ZP3 receptor
What is the 2nd step of fertilization?
Increase in Ca2+ releases acrosomal enzymes from sperm to break down zona pellucida cells
What happens during the 3rd step of fertilization?
The sperm penetrates the zona pellucida
What is the 4th step of fertilization?
Sperm and egg membranes fuse, triggering a cortical reaction from the egg (depolarization of the egg membrane)
What happen sin the 5 step of fertilization?
Sperm nucleus enters the egg cytoplasm
What does ZP3 binding cause?
The opening of Ca channels
When Ca channels open during fertilization, what does the influx of Ca cause?
The acrosomal reaction
What helps produce perforation in the acrosome?
ACE - angiotensin converting enzyme
What enzymes are released from the acrosome to break down the zona pellucida?
Hyaluronidase
Acrosin
What does the 2nd Ca2+ spike cause?
Cortical reaction from the oocyte
What does the cortical reaction do?
Cortical granuals cause the shortening of ZP2 and ZP3, tightening the matrix and blocking polyspermy
What occurs post-fertilization?
Oocyte completes 2nd meiotic division
Male and female pronuclei form and then breakdown
Mitotic spindle organizes
The mitotic spindle organizes using what?
The centriole components from the sperm tail
In interphase, a somatic cell is ___ with _N.
Diploid
2N
A somatic cell after S phase is ___ with _N (intermediate phase).
Diploid
4N
A gamete prior to meiosis II is ___ with _N (intermediate)
Haploid
2N
A gamete is ___ with _N.
Haploid
1N
HPV is highly associated with which cancer?
Cervical cancer
Why is HPV associated with cancers?
HPV early proteins E6 and E7 bind and inactivate p53 and pRb tumor suppressors - cell cycle becomes unregulated
HPV E6 also targets ___, that so cells that should have been apotptosed get maintained.
BCl2
What does Cyclin D do?
Pushes the cell cycle from G0 to G1
Where is Cyclin E found?
At the G1/S checkpoint
What is Cyclin A for?
DNA synthesis
Cyclin B is for entry into what?
Mitosis
What is the most important checkpoint of the cell cycle?
G1/S
What proteins are active at the G1/S checkpoint?
p53
Retinablastoma proteins
What occurs at the G1/S checkpoint?
Damage assessment
What is the Mid S checkpoint?
DNA checkpoint I
If there is something amiss at the Mid S checkpoint, what could it lead to?
Telomere dysfunction
Rearrangements
Amplifications
What is the G2/M checkpoint?
DNA replication checkpoint II
What is the Post-M checkpoint?
Polyploidy checkpoint
What are the proteins for ubiquitin ligases?
SCF
APC
What are the transcription factors?
Jun
Fos
Myc
E2F
What does E2F cause?
Causes transcription
If it is activated, the cell will be pushed into S phase
What are the tumor suppressors?
p53
pRb
What is the important inhibitor protein?
p21
What does cyclin D do?
Takes the cell from G0 to G1
Where is cycling E found?
At G1/S checkpoint
What is cyclin A for?
DNA synthesis
When is cyclin B seen?
On entry into mitosis
What does ARMS PCR/Allele specific PCR look for?
Detects point mutations using allele specific primers
PCR products are fractionated by what?
Gel electrophoresis
What are the steps of PCR?
Heat denature DNA
Add primers to section you want to amplify
DNA polymerase (Taq pol) copies both directions
Repeat
What is the ampicillin resistance site of plasmid pBR322?
Pstl
What is the tetracycline resistance site of plasmid pBR 322?
BamHI/SalI
How was Dolly created?
Nucleus from mammary cell wan injected into enucleated egg