Metabolism of carbohydrates iron, bile pigment

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I- DISORDERS OF CARBOHYDRATE METABOLISM :

→ INTRODUCTION : Carbohydrates are present in all tissues as glycogen. Subsequently glycogen is converted into glucose which provides glycemic control, storage in the liver and burning in the muscles. Carbohydrates are also present in the form of acid mucopolysaccharides in neutral and basic substance and in certain product secretion as mucosubstances.

→ DIABETES : Morphologically there is a hyalinization of the vascular walls and sclerosis associated with granulation cells Beta insulin-secreting islets of Langerhans. Vascular lesions can reach all territories :

  • In the retina : diabetic retinopathy.
  • In the lower limbs : parietal sclerosis of the arteries causes a reduction in flow. limp intermittente (to the effort).
  • At the level of the brain vascular sclérohyalinose lesions are the cause of ischemic stroke (hemiplegia).

→ glycogen storage diseases : Genetically determined disorders characterized by glycogen overload. They are secondary to an enzyme deficiency.

  • The hepatorenal form or disease Von Gierke Phase G6.
  • The generalized form or PUMP disease with predominant cardiac involvement.

→ LES MUCOPOLYSACCHARIDOSES : Cystic fibrosis is an example. It is linked to a metabolic disorder of mucus secretion. It is characterized by a pancreatic disease, bronchopulmonary, intestinal and hepatic.

II – DISORDERS METABOLISM PIGMENTS :

→ definition : Pigment called, substances which have an intrinsic color and are in the form of granules in tissues. It exists 2 variety :

  • Exogenous pigments, introduced into the organism (pharmaceuticals, BP, Anthracose).
  • Endogenous pigments, produced by the body (melanin, bilirubin, lipofuschine).

Cells that secrete pigments are pigmentoblastes, the pigmentophores are those phagocytose.

III- METABOLISM DISORDERS OF IRON AND PIGMENT ferric :

1- RECALL NORMAL IRON METABOLISM :

Iron is provided by food. It is absorbed by the intestinal mucosa in a form bound with apoferritin. It is carried in the blood in a form bound to another carrier protein : The transferrin or transferase. Thus iron can win :

– Either territories of Use (synthesis of Hb in the bone marrow).

– Either reserve areas (foie) or it is stored as :

  • the ferritine… .immediately mobilized reserve.
  • D’hémosiderine… .real storage form.

2- ANATOMY AND CLINICAL ASPECTS : THE hemosiderosis.

A – DEFINITION :

The hemosiderosis corresponds to excess iron accumulation in tissues. It can be primary or secondary.

B – HIGHLIGHTING :

Pigment Brun-jaunâtre intra cytoplasmique, after routine staining with HE, it appears in the form of granules.

Special coloring PERLS : pigment appears in turquoise blue.

C – SECONDARY hemosiderosis :

  • LOCALISEES : If bleeding, contusions or hematomas.

Hb released by the destruction of red blood cells is degraded, subsequently released the iron is taken up by macrophages siderophages.

  • WIDESPREAD : Ferric pigment deposits in all organs.

– constitutional hemoglobinopathies : sickle cell, thalassémie.
– chronic hemolytic anemias.
– Important blood transfusions and repeated.

D – Hemosiderosis idiopathic PRIMITIVE OR HEMOCHROMATOSIS :

DEFINITION : C is a constitutional disease, due to a genetic disorder responsible for exaggerated iron absorption leading to widespread hemosiderosis.

CLINIQUE : This disease affects male subject beyond 50 years.

melanodermia- insulin-resistant diabetes- hepatomegaly- heart failure.

and biology, there is an increase of serum iron.

anapath STUDY :

  • FOIE : Seat of a macro nodular cirrhosis hypertrophic, it is hard consistency, particular rust staining. The accumulation of brownish granules of hemosiderin is found in hepatocytes. Hepato carcinoma risk of malignant transformation.
  • PANCREAS : It is atrophic, indurated and brown tint, Seat sclerosis peri and intra lobular. The hemosiderin deposit is diffuse. The disease progresses to diabetes.
  • INFARCTION : The heart is hypertrophic, soft and flaccid.
  • SKIN : Hyper pigmentation integuments.

IV- METABOLIC DISORDERS BILE PIGMENTS :

1- RECALL METABOLISM BILIRUBIN :

The pigment is produced by the destruction of red cells in the reticuloendothelial system (rate, bone marrow). Bilirubin is transported to the liver through blood unconjugated form. In the liver, it is converted to bilirubin with an enzyme : Glycuro-transférase. It is then excreted in the bile and then passes into the intestine where it is degraded stercobilin. A small amount reabsorbed in the gut, is removed as urobilin in urine.

2- APPEARANCE CLINICAL ANATOMY :

The abnormal accumulation of pigment in the tissue, particularly in the integument and mucous membranes defines jaundice. Different types of jaundice are observed following the triggering mechanism :

a- A jaundice BILIRUBIN FREE :

  • Jaundice hemolytic by massive destruction of red blood cells in certain sepsis. The quality of free soluble bilirubin, can be attached to the basal ganglia of the brain causing kernicterus newborn.
  • Jaundice disorder glucuronide conjugation, transient ( premature neonatal jaundice), or constitutional ( disease GRIGLER NAJJAR).

b- A COMBINED jaundice BILIRUBIN :

There disorder biliary excretion or cholestasis.

  • obstructive jaundice : of biliary calculi, cancer of the pancreatic head.
  • Non obstructive jaundice : drug-induced hepatitis.

V- DISORDERS METABOLISM COPPER :

1- REMINDER :

Copper is normally present in erythrocytes, liver and brain. It is absorbed from the intestinal mucosa and transported by a carrier protein : THE céruloplasmine.

2- ANATOMY PATHOLOGICAL ASPECTS :

Ceruloplasmin deficiency seen in Wilson disease causes an accumulation of copper :

  • In the cornea or it forms the green ring KAYSER – FLEISHEIR.
  • In the brain, at the central ganglia producing a Parkinsonian syndrome.
  • In the liver : large liver cirrhosis.

WE- OTHER PIGMENTS :

  • Liposfuscin is NOT a positive fat, its rate increases with Page.
  • melanin, its highlight is performed by the reaction FONTANA.

– Either hyper producing chloasma.
– Either insufficient production… ..Vitiligo, albinisme.

Course of Dr N. lemma – Faculty of Constantine