This document discusses two cases of petrous bone cholesteatoma. It provides background on petrous bone anatomy and classifications of petrous bone cholesteatoma. It also describes the surgical approaches and considerations for treatment of petrous bone cholesteatoma, which aim to completely remove the disease while preserving vital structures like the facial nerve. Two cases of petrous bone cholesteatoma are presented and the surgical treatments used in each case.
Sinus tymapni shape and depth can influence surgical approach in cholesteatoma surgery. In the case of a shallower ST, an exclusive endoscopic exploration is chosen; while in the case of a deeper ST, a retrofacial approach is usually preferred.
Cavity obliteration is a procedure done at the end of Mastoidectomy to get a cavity-less mastoid cavity thus solving the problem of discharging post-operative cavity.
Sinus tymapni shape and depth can influence surgical approach in cholesteatoma surgery. In the case of a shallower ST, an exclusive endoscopic exploration is chosen; while in the case of a deeper ST, a retrofacial approach is usually preferred.
Cavity obliteration is a procedure done at the end of Mastoidectomy to get a cavity-less mastoid cavity thus solving the problem of discharging post-operative cavity.
Spaces of middle ear and their surgical importanceDr Soumya Singh
one of the imp topics in ENT that should be understood very thoroughly if u want to pursue as an otologist.I tried to simplify the topic with simple diagrams and models for better understanding .
Inner ear malformations and ImplantationUtkal Mishra
This slide vividly describes relevant anatomy & embryology of cochlea. It gives the reader insights into various cochlear malformations & implantation.
Perilymph Fistula can be difficult to diagnose as a standalone condition. Post-trauma symptoms such as dizziness, headache, etc. can be linked to other conditions like a traumatic brain injury with a concussion.
Spaces of middle ear and their surgical importanceDr Soumya Singh
one of the imp topics in ENT that should be understood very thoroughly if u want to pursue as an otologist.I tried to simplify the topic with simple diagrams and models for better understanding .
Inner ear malformations and ImplantationUtkal Mishra
This slide vividly describes relevant anatomy & embryology of cochlea. It gives the reader insights into various cochlear malformations & implantation.
Perilymph Fistula can be difficult to diagnose as a standalone condition. Post-trauma symptoms such as dizziness, headache, etc. can be linked to other conditions like a traumatic brain injury with a concussion.
Dr Rahul VC Tiwari - Novel Transoral Approach to the Posterolateral Maxilla and Infratemporal Region - 10th jc - DEPARTMENT OF ORAL AND MAXILLOFACIAL SURGERY - SIBAR INSTITUTE OF DENTAL SCIENCES, GUNTUR
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
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Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
2. PETROUS BONE CHOLESTEATOMA
Uncommon pathologic
condition(4-6% of all temporal
bone lesions)used to define an
epidermoid cyst of the petrous
portion of the temporal bone
A surgical challenge
considering the complex
anatomic relationship with vital
intracranial structures and the
risk of csf leak .
Two cases of petrous bone
cholesteatoma are entailed here.
3. CASE REPORT
CASE1
A 49 yr old male pt
came with H/O left ear
discharge-since 10yrs
H/O head ache-4
months
Patient also had left
facial palsy hard of
hearing & following
previous surgery for
cholesteatoma
k/c/o DM,HTN-1yr on
treatment
CASE 2
24 yr old male
presented with chief
complaints of
Left sided headache
-4mnths
And Giddiness *3
mnths
No h/o any
comorbidities
4. PAST HISTORY
CASE1
Pt underwent modified
radical mastoidectomy in
2014 (for extensive
cholesteatoma)
Radical mastoidectomy in
2015(for recurrent
cholesteatoma )
Craniotomies twice for
extradural abscess and
zygoma excision for
zygomatic abscess in 2016
CASE2
H/O MRM 8 yrsback
5. GENERAL PHYSICAL EXAMINATION
General examination:
Pt GC fair
Afebrile
Nopallor/icterus/cyanosis/lymphadenopathy/clubbing/pedal edema
CVS-s1,s2+
RS-B/L AE+
P/A-soft,no organomegaly
CNS-NFND
6. ENT EXAMINATION
PTA Right –wnl
Left- severe mixed HL
Right-wnl
Left-mild CHL
CASE1 CASE2
EXTERNAL EAR
Preauricular region normal normal
Pinna normal normal
Post auricular region Left-Scar + Right -normal Left- Scar+ Right-normal
EAC Left-Blind sac closure
Right –normal
Left-Normal
Right-normal
TM Left-Not seen Right-normal Left-normal Right-neotympanum
Fistula sign absent absent
3 point/tragal tenderness absent absent
TFT Rinne
Weber
ABC
+ve -ve
Lateralised to LEFT
Not reduced
+ve -ve
Lateralised to LEFT
Not reduced
Facial nerve Grade 5 facial palsy normal
Vestibular signs absent absent
7. CASE1- HRCT-craniotomy
defect + large cystic
destructive lesion noted in
left EAC,ME
cavity,squamous,temporal,m
astoid and PETROUS
portion and facial canal
F/s/o ? recurrent
cholesteatoma –with petrous
bone involvement
CASE2 HRCT-soft tissue
opacity note in the left
mastoid and extending into
petrous temporal bone
Middle ear appears
normal,with intact ossicles
8. CASE 2-MRI-clearly demonstrates
the extension of cholesteatoma
into petrous apex with intact ME
inner ear structures
CASE1-MRI-post radical
mastoidectomy status-soft tissue
density noted in mastoid and
middle ear extending to petrous
apex,fallopian canal involvement+
RAMASAMY 49/M
Temporal
2017 01 05
16 38 pm
BIR 3372
R
R L
TR 3760
TE 89.00
‘KK_15/150
TR 3760
TE 89.00
SP F33 5
SL 5 0/5 44
FeV 186 4s
‘KK_15/150
SP F33 5
SL 5 0/5 44
FeV 186 4s
9. DECISION
CASE1 – diagnosed as massive petrous bone cholesteatoma
pt taken up for trans cochlear approach(pt already had
grade 5 facial nerve palsy and non serviceable hearing on
left )
Case2 –provisionally diagnosed as infralabyrinthine petrous
bone cholesteatoma taken up for subtotal petrosectomty
in view of hearing preservation
MASSIVE INFRALABYRINTHINE
11. PETROUS BONE-RELEVANT
ANATOMY
Petrous bone :That part
of the temporal bone
medial to the middle ear
cleft.
Consists of base ,apex,
anterior ,inferior and
posterior surfaces
Shaped like a pyramid,
contains the semicircular
canals, vestibule,
cochlea, and carotid
artery.
12. PETROUS APEX
Petrous apex : That part of
the temporal bone medial
to the otic capsule,
between the greater wing
of sphenoid and occiput
The superior surface is formed by the
middle cranial fossa, Meckel cave& ICA
Along inferior surface is jugular bulb and
IPS
13. IAC bisects the petrous
apex into a large anterior
portion that typically
contain bone marrow and
a smaller posterior
portion derived from otic
capsule
The petrous carotid
canal and IAC are the
largest channels
traversing the petrous
apex
The Dorello canal,
subarcuate canal,
singular canal, and
Meckel cave are smaller
channels.
14. PBC-CLASSIFICATION
According to Sanna et al. [1993] PBCs can be classified into
five groups:
supralabyrinthine-geniculate ganglion
infralabyrinthine-hypotympanic and infralabyrinthine cells
infralabyrinthine-apical-infralabyrinthine compartment
extending to petrous apex
Massive-otic capsule
Apical-petrous apex
These terms describe both the location and the extent of the
lesion.
15. ROUTES OF SPREAD
Extension of acquired cholesteatoma into petrous occurs
in large cholesteatoma and in well pneumatized petrous
bone
In medial extension ,cholesteatoma follows course of least
resistance & erodes thin wall of petrous air cells
1.Infralabyrinthine-below cochlea & IAC,may break into
jugular fossa
2.Anterosuperior-above cochlea,involving geniculate
ganglion&extending into supra meatal area of petrous bone
3.Posterosuperior-between limbs of Superior SCC to
reach fundus of IAC
16. 1.Subaarcuate
via arch of scc-FRECKNER
2.Retrolabyrinthine
Superior to lscc & posterior to superior
scc-THORNWALDT
3.Infralabyrinthine(hearing preserving)
inferior to posterior scc
posterior to VII nerve and superior to
jugular bulb[DEARMIN &FARRIOR]
4.Subcochlear/infracochlear-(hearing
preserving)hypotympanic air cell tract
between ica,jugular bulb and
cochlea[FARRIOR]
5/6.peritubal–
b/w ica,cochlea and tegmen
5-Ramdier/lempert
6-Kopetsky/Almoor
7.Middle cranial fossa (hearing
preserving) EAGLETON
17. TREATMENT PROTOCOL
Main factors to be considered are
(1) complete eradication of the disease
(2) preservation of facial nerve function,
(3) prevention of CSF leak and meningitis,
(4) Cavity obliteration
(5) hearing preservation whenever feasible
18. If the patient presents with preserved hearing, four routes are possible:
1.transcanal infracochlear,
2.Transsphenoidal
3. Infralabyrinthine- but limited access, especially in patients with high
jugular bulb
4.middle cranial fossa- but it does not allow a permanent drainage pathway,
and some degree of temporal lobe retraction is necessary, which could
result in brain injury
If hearing is not preserved, there are two more options:
1.translabyrinthine
2. transcochlear
Trans otic approach preserves facial nerve
19. TREATMENT PROTOCOL
SUPRALABYRINTHINE
Hearing normal sensory neural HL or
No e/o fistula in cochlea e/o fistula in cochlea
Middle fossa approach with subtotal petrosectomy/
Transmastoid approach enlarged translabyrinthine /
transotic approach with
cavity obliteration
20. Infralabyrinthine infralabyrinthine apical
(hearing preservation isnt possible)
N Hearing SNHL VII N normal VII N palsy
Subtotal transotic transotic/ IFTB+ modified
petrosectomy IFTB Transcochlear approach A
21. Massive Apical & those with extn to clivus,nasopharyn
Hearing preservation not possible & sphenoid sinus
VII N nrml VII N palsy
hearing N SNHL SNHL+VII palsy
VII n nrml VII palsy
Transotic MTCA
IFTB IFTB+TO IFTB+MTCA
22. CONCLUSION
• With thorough pretreatment evaluation of location and extent of lesion ,
meticulous radiological assessment, planning and execution, the difficult
terrain of petrous apex can be approached and dealt with successful
results
• Unlike any other lesion of the petrous apex ,cholesteatoma has the
advantage of total removal and disease clearance in the hands of an
experienced surgeon with meticuluos dissection ,by simply foolowing the
lesion
• Classification is important to decide the appropriate surgical approach.
• The facial nerve requires special consideration as it gets involved in
almost all the cases and is a cornerstone of management.
• Radical removal takes priority over hearing preservation even in only
hearing ears with the possibility of hearing rehabilitation (CI, BAHA and
Soundbridge).
• Regular follow-up is mandatory