This document discusses flaps in surgery. It begins with an introduction defining a flap as a vascularized block of tissue transferred from a donor site to another location for reconstructive purposes. The history of flap surgery is then summarized, noting early examples from India in 600 BC and pioneering work by Gillies in the early 20th century. Classifications of flaps are described based on congruity, circulation, and anatomical components. Common muscle and myocutaneous flaps are also outlined.
Examination of Swelling in a patient is always a task for MBBS students. This PPT provides the students, how to elicit a history & also the easy way to examine a swelling.
compartment syndrome, causes, compartments of legs,compartments of forearm,compartments of hand,compartments of foot, compartments of arm,compartments of thigh,fasciotomy of leg,fasciotomy of forearm, fasciotomy of hand,fasciotomy of foot, fasciotomy of thigh, fasciotomy of arm
Examination of Swelling in a patient is always a task for MBBS students. This PPT provides the students, how to elicit a history & also the easy way to examine a swelling.
compartment syndrome, causes, compartments of legs,compartments of forearm,compartments of hand,compartments of foot, compartments of arm,compartments of thigh,fasciotomy of leg,fasciotomy of forearm, fasciotomy of hand,fasciotomy of foot, fasciotomy of thigh, fasciotomy of arm
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Flap coverage in upper extremities in trauma VishalPatil483
SEMINAR PRESENTED BY DR VISHAL PATIL ,IN THE DEPT OF TRAUMA SURGERY AND CRITICAL CARE, AIIMS RISHIKESH
INCLUDES-INTRODUCTION-CLASSIFICATIONS OF FLAP-COMPLICATIONS RELATED TO FLAP COVERAGE- FLAP USED IN HAND AND UPPER EXTREMITY SOFT TISSUE RECONSTRUCTION WITH PICTURES OF IT
FLAPS IN ORAL AND MAXILLOFACIAL SURGERY (monday ppt).pptxaasthamoza
Method and type of flaps used for head and neck reconstruction. Comprising of local regional and free flaps. Indications and pitfalls in each type of flap .
A power point on the various types of flaps and their respective indications. This presentation briefly describes the various flaps and how to care for flaps.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
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.
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 .
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
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Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
2. Contents
• Introduction
• History
• pathophysiology
• Graft vs flap
• Classifications of flaps
• Principles of flap surgery
• Post operative assessment of flap
• complications
3. Introduction
• A flap is a vascularized block of tissue that is
mobilized from its donor site and transferred to
another location, adjacent or remote, for
reconstructive purposes.
4. Introduction cont..
• A flap is used :
• To reconstruct a large primary defect
• Replace tissue loss during trauma or surgical
excision.
• Provide padding over bony prominences.
• Bring in better blood supply to poorly
vascularizedbed.
• Improve sensation to an area{sensate flap}
6. History
• Origin in india:In 600
BC, Sushruta Samita
described operations
for nasal
reconstruction—, since
amputation of the nose
(an organ of "respect
and reputation") was
common as criminal
punishment.
• He used cheek flap for
reconstruction of nose.
7. History cont..
• the first muscle flap of
recorded history
debuted in 1906.
• Louis Ombredanne of
Paris described the use
of the pectoralis minor
muscle for breast
reconstruction
following mastectomy.
8. History cont..
• Sir Harold Delf Gillies:
• considered the father
of plastic surgery.
• Pioneer in facial injury
repairs.
9. Differences between flap and
graft:
graft flap
Limited to transplantation of skin Can carry other tissues
Depends on recipient site on nutrion Has its own blood supply
Cosmetic –may discolor or contract Better color take and less likely to
contract
Less adaptable to weight bearing Most adaptable to weight bearing
Less able to survive on a bed with
questionable nutrition
Can be used on a bed with questionable
nutrition
Requires pressure dressing Does not requires pressure dressing
Cannot bridge defects Can bridge defects
10. Physiologic factors affecting flap
survival:
• includes-
• 1.blood supply to the flap through its base.
• 2.formation of new vascular channels between flap
and recipient bed.
• 3.perfusion pressure of the supplying blood vessel.
11. pathophysiology
chronologic changes of a flap and the recipient site after
elevation and transfer:
• After 10-24 hours - Decreased arterial supply;
congestion and edema; dilation of arterioles and
capillaries
• After 1-3 days - Increased number and quality of
anastomoses between flap and recipient bed; increased
number of small vessels in pedicle
• After 3-7 days - Reorientation of vessels along the long
axis of the flap; anastomoses created at 1-3 days now
functionally significant
• After 1 week - Circulation well established between flap
and recipient bed
• After 2 weeks - Continuous maturation of anastomoses
• After 3 weeks - Flap achieves 90% of its final circulation
13. Classification of flaps cont..
Based on congruity:
A. local flap:
• A local flap implies that
the tissue is adjacent to
the open wound in
need of coverage.
• Eg. A wound on lip may
be repaired by a flap on
adjacent cheek
14. Classification: Based on
congruity:cont..
• B. Regional flap:
• Skin flap is not from the adjacent area but from the
same region
• Eg.wound on the tip of the nose might be repaired
with a flap from forehead.
• C. Distant flap:
• Tissue transferred from an non contiguous
anatomic site (ie, from a different part of the body)
is referred to as a distant flap.
15. Classification: Based on
congruity:cont..
• Distant flap Is of two types:
1.pedicled flap: is transferred while flap is still
attached to their original blood supply.
2.Free flap: Free flaps are physically detached from
their native blood supply and then reattached to
vessels at the recipient site.
This anastomosis typically is performed using a
microscope, thus is known as a microsurgical
anastomosis.
17. Classification: Based on circulation
• A. Axial pattern flap:
• An axial pattern flap
contains atleast one
direct cutaneous
branch blood supply
along its longitudinal
axsis.
18. Classification: Based on circulation
B.random pattern flap:
• A myocutaneous flap w
ith a random pattern of
arteries, as opposed to
an axial pattern flap.
19. Classification: On the basis of
anatomical content:
1.Skin flap
2.Muscle and myocutaneous flap
3.Fascia and fascio cutaneous flap
20. Skin flap:
• Uses:
• 1.recipent bed with poor vascularity
• 2.coverage of vital structures
• 3.reconstructing full thickness structures e.g.eyelid
,cheek, nose, lip, ear etc.
• 4.padding of bony prominences
21. Skin flaps:cont..
Types :
1.Those rotating around a pivot point:
• a)rotation flap
• b) transposition flap
• c)interpolation flap
2.advancement flaps
• a)single pedicled advancement flap
• b) V-Y advancement flap
• c)bipedicled advancement flap
22. Skin flaps:cont..
A.Rotation flaps :
are semicircular flaps of skin and subcutaneoustissue
• that revolve in an arc around a pivot point to shift
tissue in a circle.
• Rotation flaps provide the ability to mobilize large
areas of tissue with a wide vascular base for
reconstruction
25. Skin flaps:cont..
• C. interpolation flap: is
from a near by but not
immediately adjacent
donor site and
transposed either
above or below the
intervening skin to
recipient defect.
26. Skin flaps:cont..
Advancement flap:
• Advancement flaps move directly forward and rely
on skin elasticity to stretch and to fill a defect.
• No rotational or lateral movement is applied
• It is of 3 types:
A.single pedicle advancement flap.
B.bipedicle advancement flap.
C.v-y flap advancement flap.
27. Skin flaps:advancement flap cont..
• Single pedicle advancement flap: Here the
rectangular skin flap is moved forward by virtue of
its elastic properties.
• Bipedicle flap: here an insicion is made parallel to
the defect and the flap is undermined and
advanced
28. Skin flaps:advancement flap cont..
V-Y advancement flap:
V-Y advancement flaps advance skin on each side of
a V-shaped incision to close the wound with a Y-
shaped closure.
• The V-Y pedicle plasty technique allows most
patients to regain sensation and two-point
discrimination in the fingertip
29.
30. Skin flap: types cont..
Rhomboid flaps:( limberg flap.)
• rely on the looseness of adjacent skin to transfer
• a rhomboid-shaped flap into a defect that has been
converted into a similar rhomboid shape
31. Skin flap: types cont..
• Z-plasty:
• Z-plasty transposes two interdigitating triangular
flaps without tension to use lateral skin to produce
a gain in length along the direction of the common
limb of the Z.
32. Skin flap: types cont..
Common indications of z plasty:
• lengthening of a contracted linear scar across a
flexor crease.
• changing the direction of a cosmetically
unfavorable scars.
33. Muscle and myocutaneous flap:
• Consideration of a muscle as a potential flap is
possible because muscles have independent,
intrinsic blood supply.
• Compared with skin flaps, muscle flaps are less
stiff,and more malleable to conform to wounds
with irregular three dimensional contours.
• Muscle flaps are classified according to their
principal means of blood supply and the patterns of
vascular anatomy and according to mode of
innervation.
34.
35. Common muscle flaps:
Tensor Fascia Lata:
• Applications- Coverage of lower abdominal wall,
perineum, ischium and sacrum
• Vascular Anatomy: Ascending branch lateral
circumflex femoral (off Profunda femoris)
36. Common muscle flaps:
Trapezius:
• Applications – Skull, head
and neck, Oral cavity,
posterior trunk and
shoulder. Mandible facial
reanimation.
• blood supply: Dominant:
Transverse cervical artery
Length . Minor: Branch of
Occipital artery. Dorsal
Scapular artery.
37. Common muscle flaps:
Gluteus Maximus:
• Applications – Sacrum ,
Ischium, Trochanter,
breast reconstruction
• Vascular Anatomy
:Dominant: Superior
gluteal artery Inferior
Gluteal artery ,Minor:
First perforator of
Profunda femoris ,
Intermuscular branches
of lateral circumflex
femoral artery.
38. Common muscle flaps:
Pectoralis Major
myocutaneous flap:
• Applications: Coverage,
Reconstruction, Functional
transfer, Free flap.
• Vascular Anatomy:
Dominant: Pectoral branch
of Thoracoacromial
artery.Minor :Pectoral
branch of lateral thoracic ,
Minor Segmental Internal
mammary perforators.
39. Common muscle flaps:
Transverse rectus abdominis
muscle flap (TRAM flap):
• It is either superior pedicle
based on the superior
epigastric vessels or inferior
pedicle based on the inferior
epigastric.
• Superior pedicle based flap is
used to cover
postmastectomy area or
chest wall defect.
• Inferior pedicle flap is used to
cover the defects in groin and
thigh.
40. Common muscle flaps:
Serratus Anterior :
Applications – head and neck, Thorax, axilla,
posterior trunk, breast reconstruction and free tissue
transfer.
Vascular anatomy: Dominant Lateral thoracic
Branches of Thoracodorsal artery.
41. Myocutaneous flap:
• A musculocutaneous flap, also called a
myocutaneous flap, is a muscle flap designed with
an attached skin paddle.
42. Fascia and Fasciocutaneous Flaps:
• Fasciocutaneous flaps are tissue flaps that include
skin, subcutaneous tissue and the underlying fascia.
• They can be raised without skin and are then
referred to as fascial flaps.
• fasciocutaneous flaps to provide coverage when a
skin graft or random skin flap is insufficient for
coverage (eg, in coverage over tendon or bones).
43. Fascia and Fasciocutaneous Flaps:
cont..
• Because they are less bulky, fasciocutaneous flaps
are indicated when thinner flaps are required
• Fasciocutaneous flaps are not as resistant to
infection as muscle flaps. Monitoring flap failure
occasionally can be difficult
44. Fascia and Fasciocutaneous Flaps:
cont..
classification of fasciocutaneous flaps is based on
vascular anatomy:
45. Principles of flap surgery
Principle I: Replace Like With Like
when a part of one's person is lost, it should be
replaced in kind, bone for bone, muscle for muscle,
hairless skin for hairless skin, an eye for an eye, a
tooth for a tooth
46. Principles of flap surgery cont..
• Principle II: Think of Reconstruction in Terms of
Units
• human beings may be divided into 7 main parts:
the head, neck, body, and extremities. Each of
these body parts can be further subdivided into
units.
• The head, for example, is composed of several
regional units: scalp, face, and ears. All of these
different units and subunits must be considered
and reproduced during reconstruction.
47. Principles of flap surgery cont..
principle III: Always Have a Pattern and a Back-up
Plan
• the surgeon should ask him or herself "what do I do
next if this fails?" Proceed to the operating room
only after answering this question definitively
• Principle IV: Never Forget the Donor Area:
48. Postoperative flap monitoring:
• The gold standard of postoperative flap monitoring
is clinical observation.It includes:
• 1.flap color
• 2.capillary refilling time
• 3.surface temperature monitoring
• 4.Blanching assesment
50. Causes of flap failure:
• poor anatomical knowledge when raising the
flap(such that the blood supply is deficient from
the start)
• flap inset with too much tension.
• local sepsis or a septicaemic patient.
• the dressing applied too tightly around the pedicle.
