Science Hub. "Dr.Samy William"

Hepcidin — the iron gatekeeper

Hepcidin is the liver-derived peptide hormone that controls systemic iron: it binds ferroportin and blocks iron export from enterocytes and macrophages. When hepcidin is high, serum iron and transferrin-saturation fall even if body iron stores are normal — the core mechanism behind anemia of inflammation.

Why labs should care:
• Differential diagnosis power. Measured hepcidin helps distinguish true iron-deficiency anemia (low hepcidin) from anemia of chronic disease / functional iron deficiency (high or normal hepcidin), which directly affects whether oral iron will work. Multiple recent reviews and cohort studies support hepcidin as a useful adjunct in this problem set.
• Therapeutic prediction. Elevated hepcidin predicts poor response to oral iron and may help guide choice of IV iron or anti-inflammatory strategies in complex patients.

Assays — what labs should know before promising clinicians results:
• Two main families: mass-spectrometry (LC-MS/MS) and immunoassays. LC-MS methods are specific and harmonizable; commercial immunoassays are convenient but tend to read higher than MS and vary between platforms, especially in high inflammatory states. Know which method your lab will use and don’t mix numbers from different platforms.
• Standardization is improving but not perfect. Proficiency studies show intermethod variability — if you adopt hepcidin testing, plan a method comparison and participate in external QC.

Pre-analytics & reporting:
• Use the specimen and processing validated for your chosen assay (EDTA plasma vs serum), lock time-to-centrifuge, avoid hemolysis, aliquot and store at −80 °C for batch testing. Report specimen type and method with every result. Clinical interpretation without those metadata is risky.

How clinicians will use a hepcidin result:
• Low hepcidin + low ferritin/low TSAT → true iron deficiency — oral iron usually appropriate.
• High/normal hepcidin + low TSAT but normal/elevated ferritin → functional iron sequestration (inflammation, CKD) — consider IV iron or treat inflammation; oral iron likely to fail.
• Borderline cases → use hepcidin alongside ferritin, CRP, transferrin saturation and clinical context (infection, CKD, pregnancy, recent transfusion).

Practical rollout checklist for labs:

Decide use case (diagnostic reflex for borderline anemia, research, or clinic-requested test).

Choose method and run method-comparison against an external reference lab.

Lock pre-analytic SOPs and train collection staff.

Implement QC (pooled QCs, participate in proficiency testing).

Provide clear LIS guidance so clinicians know how to act on the result.

Does your lab run hepcidin? what single validation or pre-analytic snag would you warn others about?

🧠It fits in the palm of your hand... but it can save your life! 🙌💡

What you see here is not just a network of arteries, it's a **Masterpiece of Human Anatomy**: **The Willis Circle**. 🧠💫

Located at the base of the brain, this arterial ring forms a **vital highway** that supplies oxygenated blood to the most sensitive regions of the cerebellum. But the most surprising thing is not his shape... it's their function of **rescue! ** 🚑

When a cerebral artery gets clogged (like in a **stroke**), this **natural bypass** can redirect blood flow through alternate routes. It's the **emergency system** evolution has given us! 🔄

But, beware: **less than half the people** have a fully functioning Willis Circle. Just that fragile. It's just that unique. 🧐

Every bifurcation, every curve, every anastomosis is a work of biological engineering designed to **protect the most valuable thing: our brain. ** 🔒🧠

Even if you don't see it, **in there**, silently, there are mechanisms that fight to keep you alive. And that, **is what makes medicine so fascinating**. 💉❤️

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The Brain 🧠🧅

Myalgic encephalomyelitis, also called chronic fatigue syndrome or ME/CFS, is a long-term condition that can affect different parts of the body. The most common symptom is extreme tiredness. The cause of ME/CFS is unknown.

ME/CFS can affect anyone, including children.

Symptoms of ME/CFS
The 4 main symptoms of ME/CFS are:

feeling extremely tired all the time (fatigue), which can make daily activities like taking a shower, or going to work or school, difficult
sleep problems, including insomnia, sleeping too much, feeling like you have not slept properly and feeling exhausted or stiff when you wake up
problems with thinking, concentration and memory (brain fog)
symptoms getting worse after physical or mental activity, and possibly taking weeks to get better (also called post-exertional malaise, or PEM)
Some people with ME/CFS may also have pain in different parts of the body or flu-like symptoms, such as high temperature, headache and aching joints or muscles.

The symptoms of ME/CFS are similar to the symptoms of some other illnesses, so it’s important to see a GP to get a correct diagnosis.

Meet your Reticular Activating System (RAS)

A bundle of nerves. Your built-in “autopilot”. And the No 1 key to changing behaviour, reaching goals and unlocking your team’s potential. Would you believe that the most powerful tool for understanding and changing human behaviour – yours and that of all your colleagues, teams and friends – is a small part of your brain called the Reticular Activating System?

“If you’ve ever asked why people behave the way they do, and how you can sustainably change that behaviour for the better, then this is for you.”

So, if you’ve ever asked why people behave the way they do in your company (because it ultimately affects everyone’s performance), and how you can sustainably change that behaviour for the better, then this is for you: We look at the Reticular Activating System, it’s functions and how to unlock the things you want for your company.

WHAT IS THE RETICULAR ACTIVATING SYSTEM?
The Reticular Activating System (RAS) is a bundle of nerves that sits in your brainstem. And its job is to regulate behavioural arousal, consciousness and motivation. What that means is, the RAS is able to control what incoming information (stimulus) you’re aware of, so that you’ll be motivated to behave in a certain way.

But what does that mean? It’s a “guard” that sits between your brain and your senses (sight, hearing, touch etc.) and filters what information gets through and what doesn’t. Bet you didn’t know that your brain is not processing everything that happens around you!

Why? It’s a survival mechanism. At any given time, only a certain amount of information is actually useful to your brain.
For example: If there’s a tiger about to attack you, that’s the only information your brain needs to drive you to action – RUN for your life! It doesn’t need to know what colour the grass and flowers are, or how the air smells, or what song is playing in the background – those things are all irrelevant information.

Your RAS is the thing that analyses what incoming information is actually relevant to you (and your survival), and lets only the most important stuff through – it actively blocks the rest of the info (so you are not aware of it).

Apoptosis
is the process of programmed cell death.
It is used during early development to eliminate unwanted cells; for example, those between the fingers of a developing hand.
In adults, apoptosis is used to rid the body of cells that have been damaged beyond repair.
Apoptosis also plays a role in preventing cancer.

When an object is placed between two parallel concave mirrors, a series of reflections occurs due to the nature of concave mirrors and their ability to converge light. Here’s a step-by-step breakdown of what happens:

Initial Reflection: The object reflects off the first concave mirror.
The image formed by this reflection is virtual and upright, located behind the mirror at a distance determined by the mirror's focal length and the object's distance from the mirror.

Second Reflection: The image formed by the first mirror acts as a virtual object for the second mirror. The second concave mirror will also reflect this image, creating another virtual image.

Multiple Reflections: This process continues, with each mirror reflecting the image formed by the other. If the mirrors are perfectly parallel and the object is placed at an optimal distance, the reflections can create a series of images that can appear to be infinitely repeating.

Image Characteristics: The images formed will generally be virtual, upright, and reduced in size with each reflection.
However, depending on the exact placement of the object relative to the focal points of the mirrors, the nature of the images (such as size and clarity) may vary.

Resulting Image: If the object is placed exactly at the center of the mirrors (the center of curvature), it can result in a more complex pattern of reflections, potentially leading to a situation where multiple images overlap or become difficult to distinguish.

Overall, the scenario creates a fascinating visual effect, often seen in setups like funhouse mirrors or optical devices designed for artistic or scientific purposes

Butterfly Vs moth..
What are the differences between butterflies and moths?

Although both of these fluttering insects come under the classification Lepidoptera, they possess many differences that classify them as a butterfly or a moth.

Spotted a flying beauty and not sure whether it’s a butterfly or a moth?

These 8 differences between butterflies and moths will have you classifying that critter in no time!

1.Their Wings When Resting
difference between butterflies and moths
One of the most obvious differences between butterflies and moths is their resting wing position. Moths rest with their wings open, whereas butterflies tend to rest with their wings closed. However, many butterflies “sun bake” with their wings open.

2. Nocturnal vs Diurnal
Butterflies are active during the day (diurnal), whereas moths are active at night (nocturnal).

3.Antennae Shape
butterfly antennae vs moth antennae
Left: Moth antennae of a Hercules Moth and a Zodiac Moth.
Right: Antennae of a Cairns Birdwing Butterfly
If you look closely at the antennae of both moths and butterflies, you will notice that they are very different shapes.
Moth antennae tend to be leaf or feather shape. Butterfly antennae tend to be long, bare and eject from the head in a club shape. They also have a bulb at the end.
Although this is normally the case, there are some moths that have slender antennae rather than feathered, such as the Zodiac Moth, however the antennae on these moths tend to be straight rather than curved.

4. Frenulums
Moths have a frenulum, which is a wing coupling device that ensures the wings travel together during flight. Butterflies do not have this.

5.Pupae
moth cocoon vs butterfly pupa
Left: a Hercules Moth Cocoon.
Right: a Birdwing Butterfly Pupa
In the metamorphism from caterpillar to butterfly, caterpillars spin a pupa consisting of hardened protein.
On the other hand, moth caterpillars form a silk pupa, which is known as a cocoon.

Despite this being a generalised rule, there are some exceptions. Prime examples include Gypsy Moths form a pupae that resembles that of a butterfly and the Parnassius Butterfly, which makes a cocoon.

6. General Appearance
butterfly vs moth what is the difference

Widely speaking, moths tend to be stockier and have furry bodies, whereas butterflies are smooth and lean. This difference in appearance is due to scale size; butterflies possess far smaller scales.

7. Eyes
As moths are nocturnal and butterflies are diurnal, it makes sense that the two species would adapt to have different eyes to suit their light conditions.
In general, moths have superposition eyes, which reflect light at the same angle that they take it in. This type of eye creates images up to 1000 times brighter than acquisition eyes, but sacrifices image quality. On the other hand, butterflies have apposition eyes, which work by gathering multiple images and combining them in the brain.

8. Colour
differences between butterflies and moths
Top: Ulysses Butterfly, Bottom: Hercules Moth
In general, moths tend to be duller and less vibrant in colour, with less intricate and striking patterns. Although this is a generalised rule, some moths, such as the Madagascan Sunset Moth are incredibly colourful and striking,

Vertebral column of a man:
C = cervical (neck region)
T = Thoracic (chest region)
L = Lumber (abdominal region)
Then Sacral & coccygeal