- Blood groups - ABO system.

- Many systems have been discovered to differnetiate bloog groups,the most famous system is ABO system.



- ABO system represent antigenic components on the surface of RBCs according to which
this system was made.
- O RBCS means that there is no antigens on the surface of RBCs so we can give O RBCS
to all other types of RBCs groups.

- B RBCS means that there is B antigens on the surface of RBCs so we can give B RBCS
Only to B person or AB person.

- A RBCS means that there is A antigens on the surface of RBCs so we can give A RBCS
Only to A person or AB person.

- AB RBCS means that there Are both A,B antigens on the surface of RBCs so we can give AB RBCS Only to AB person.

-Sudden Infant Death Syndrome.

Sudden Infant Death Syndrome.
(SIDS) Or COT death

Def:- Sudden unexpectrd death in infant of appearant good health,without giving a commonly accepted cause at autopsy.

The cause:- undefinite but may be:-

1. Suffocation.
2. Infections:fulminant viral infections.
3. Impaired respiratory reflexes.
4. Diet : Improper diet causing nutritional deficiences or hypernatremia.
5. Sensetivity to milk proteins.
6. Cardiac conduction disorders.
7. Co or Co2 poisoning.
8. Overlying in the early life.
9. Thermal: Hyper or hypothermia.

*Features of the syndrome:

- Age: () 2weeks and 2 years with a peak 2-3 months of life.

- Sex : males more than  females.

- Social level: low socioeconomic level more than high socioeconomic level.

- Whether: cold winter more than hot summer.

- Twins more than single babies due to:

•   increase icidence prematurity.
•   low birth weight.

- Some Types of prints.

- Really there are many types of prints which help

in identification of individuals allover the world,

especially in the field of forensic medicine and crimes.

- We will take a quick review about some of them:

1- Fingerprints..from here.

2-DNA fingerprinting...from here.

3-Foot prints:

- are the impressions or images left behind by a

person walking made by sole of the foot and


skin pattern of toes and heel.

- WE can collect important information from them

that helps tell about the person that left them behind.

-Information concerning the approximate height of the

person and possibly the walking habits of the person

are two pieces of information that can prove useful

in a criminal investigation.

4-palm prints.

5-Iris print (recognition):

-Are used to screen individuals who are trying to gain

access to more highly secure places or accounts,

not to scan the general public at random.

-By using camera technology, with subtle infrared

illumination reducing specular reflection from

the convex cornea, to create images of the detail-rich,

intricate structures of the iris. Converted into

digital templates, these images provide

mathematical representations of the iris that yield

unambiguous positive identification of an individual.

6-Retinal print:the same idea of iris.

6-Voice print:

-The fact that voice follows a particular pattern,

whatever the language spoken.

- The FBI is trying to develop a system that

could make your voice as unique and recognizable

as your fingerprint called FASR system.


7-Ear print:

Burglars often listen at windows and doors,

leaving an earprint behind, which, just like

a finger print, can be used to trace them.

Ears are unique in size, shape and structure.

Scientists use these traits to develop biometric

scans of the ear. In ear scans, a camera creates

an image of the ear that is analyzed for

identifying characteristics.

8-Thermal footprint:

our bodies emit thermal energy which by special systems

can recognize the persons after their presence

in some places e.g scene if the crimes.


9- Air sinus print:

Pattern of skull's frontal air sinuses ,Outline is

unique and comparisons with antemortem X-rays are useful.

10-Lip print:-

lip print identification is generally acceptable

within the forensic science as a means of positive

identification because it appears in the scene of the crime.

see you, Dr Ibrahim

- Sir Hershel -1858 .

Sir William Herschel, Chief Magistrate of the Hooghly

district in Jungipoor, India, first used fingerprints on

native contracts.

On a whim, and with no thought toward personal

identification, Herschel had Rajyadhar Konai, a local

businessman, impress his hand print on a contract.

The idea was merely "... to frighten [him] out of

all thought of repudiating his signature." The native was

suitably impressed,

- DNA fingerprinting.

- The chemical structure of everyone's DNA is the same.

- The only difference between people (or any animal)

is the order of the base pairs.

- There are so many millions of base pairs in each

person's DNA that every person has a different sequence.

-There are high diversity due to presence of non encoding

areas in the strand either in the genetic area

or outside it see here...

- Using these sequences, every person could

be identified by the sequence of their base pairs.

- Each person has a unique DNA fingerprint,

except monozygous (identical) twins.

- DNA fingerprint is the same for every cell,

tissue, and organ of a person. It cannot be

altered by any known treatment. Consequently,

DNA fingerprinting is rapidly becoming the primary

method for identifying and distinguishing among

individual human beings.

- These patterns do not, however, give an

individual "fingerprint," but they are able to

determine whether two DNA samples are from the

same person, related people, or non-related people.

Scientists use a small number of sequences of DNA

that are known to vary among individuals ,

and analyze those to get a certain probability of a matching.

------------------------------------------------

**Practical Applications of DNA Fingerprinting**

1. Paternity and Maternity :

when a father deny that a certain child is belonging

to him Or tow sets of parents claim on one child.

2. Criminal Identification and Forensics:

- In living (strong evidence of involvement

in assault,rape, disputed paternity)

as DNA isolated from blood,hair, skin cells,

or other genetic evidence left at the scene

of a crime can be compared with the

DNA of a criminal suspect .

- In Dead (DNA survives in bone for many years,

comparison of DNA with family members)

3. Personal Identification .

Enjoy it,see you,

Ibrahim

- DNA strucure and terminology.

Chromosomes are thread-like structures located inside the nucleus of cells. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.

see the picture which illustrate that also show the true genetic content & non genetic areas....

Promoters: are DNA sequences adjacent to the beginning of the genes and control gene activation.

 

Introns are sequences inside the gene although they do not code for protein sequence they are necessary for correct coding.

 

Exons are the regions inside the gene between introns that contain the coding DNA sequences. 

 

Most of the harmful mutations occur in exons and as a consequence change the structure of the coded protein.

 

- Fingerprints.

-friction skin (i.e. palms and soles) have a

impressions due to presence of ridges & grooves .

- These impressions made by dermal papillae in the dermis.

- Finger prints appear in the 4th month intrauterine life.

-Sweat glands open through minute openings on the

summits of the ridges. The sweat contains fat.

- When the skin is applied to a glistening

non-absorbable surface an impression is left behind.


Principles of fingerprint identification :

-fingerprint patterns are unique

(1 in 64 billion chance of 2 prints being identical).

-FBI has over 100 million records, no two of which are alike.

-Fingerprint pattern of an individual remains

unchanged throughout life.

-Reversible atrophy occurs in certain diseases

(coeliac disease, dermatitis).

- Some people have some skin diseases which

prevent normal formation

of fingerprints (may be genetically ).

-Permanent impairment occurs in leprosy and after

exposure to radiation.

-Attempts to mutilate fingerprints are sometimes made.

- If only the epidermis is destroyed there is no

alteration in ridge pattern.

-If dermis is destroyed additional points of

identification are created.

Types:

1-Arches.

2-Loops.

3-Whorls .

4-composite: of more than one type.

-----------------------------

poroscopy

Def: study of the pores of the sweat glands which

present at the ridges of the prints.

Position of the pores requires higher resolution scanner.

---------------

N.B: There are artificial finger prints which

used by criminals for misleading.

see you,

Dr Ibrahim

- Forensic Medicine.

- Forensic Science :-

Application of knowledge of science (biology, chemistry, physics ,….etc) for  purposes of law and justice.(1)

- Forensic medicine (legal medicine) :-

 Is a branch of medicine that applies the principles and knowledge of
 the medical sciences for administration of law and  justice .(1)

- Forensic medicine is a medical science that studies :-

• Identification الإستعراف
• Somatic and Psychiatric injuries,
• Tanatology “ science of Death. ”
• Autopsy.
• Medical ethics أخلاق المهنة
• Forensic laboratory services)e.g Toxicology, Histopathology, Serology, Biochemistry, Molecular Biology, DNA laboratory, Medical Imagination and Radiology,Microbiology, Physical Technology)

- Forensic medical expert have to know medical sciences very well to use that in his final medical decisions.

- Characteristics of forensic medical expert:-

1- Caution; He must be accurate and precise in his result and decisions.
2- Intelligence; He must be a good observant.
3-Honesty and accuracy.
4-Good medical knowledge of all medical branches.
5- Well knowledge of criminal sciences and criminal law.
- The expert witness differs from the ordinary witness as he did not see or hear the incident in dispute (النزاع), he gives evidence of scientific fact and he gives an opinion based on professional knowledge and experience, though he may subsequently see the body, or the vehicle, or the instrument, or the scene.(2)


- The expert should explain that his evidences have scientific limitation , so the expert should be under an obligation(ملزم) to make sure that the court does not, unwittingly, use his evidence without realizing its scientific limitations.


- N.B:-The first ever medico-legal expert is considered to be “Imhotep” (1)
 

-Branches of forensic medical centre:-

• Clinics:-

to examine the somatic and psychiatric injuries, and to determinate the age of live people through clinical forensic & forensic psychiatric .

• Morgue(مشرحة) :- to perform autopsy.

• Laboratories:-

-Forensic Pathology:- To study histopathology samples.
-Forensic Medical Imagination and Radiology.
-Forensic Toxicological:-To investigate the poisons, and drugs of human samples.
-Forensic Immunological :- To investigate the biological traces ( blood, semen, saliva, hair,…etc) To determine the -blood system groups, and DNA fingerprint.
-Forensic Physical Technology :- To reconstruct the accidents, the crimes, the face features, the body features, traffic accidents, firearms, and falls from heights….. to study the fingerprints.

-References:-

• Forensic medicine ,Prof.Dr.Abd El-Aziz Ghanem,Mansoura, pp.(i-iii),(2.
• Expert Forensic Evidence, Alec Samuels, Medicine, Science and the Law, 1974,volume 14, pp. 17-25.