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The Marrow Thieves p. 154-191
Quiz by Barbara Fischer
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TYPES OF BONE observation of bone: Compact (cortical) bone - dense areas without cavities Spongy (cancellous) bone - areas of trabeculae forming interconnecting cavities Example: long bone Ends (epiphyses) have spongy bone covered by (thin) compact Shaft (diaphysis) - compact bone with some spongy bone lining the marrow cavity
Endochondral ossification (cont’d) Secondary ossification center appears in the epiphysis (shortly after birth); no bone collar During remodeling, cavity is produced that fills with bone marrow 2 areas of cartilage remain Articular Epiphyseal (responsible for bone growth in length) Closure of plates is complete by age 20 Once closed, growth in length is stopped
[t comes from the GREEK name "Epilepsia" which means "taking hold of or seizing". - It is a disorder characterized by: recurrent seizures. SEIZURES R ectment transient attacks of: R epresent: R esult from: ASSOCIATED WITH: somatic, psychic, or, autonomic clinical featmes. clinical features of abnormally hyperexcitable cortical neurons. paroxvsmal and excessive electrical neuronal discharges. EEG changes & may be disturbance of consciousness. same causes of convulsions 1. Idiopathic epile~ • It is the commonest cause. no cause can be detected ( 65 % ) • It may be associated with positive family history in some cases. • It starts in the l st & 2nd decades in the form of: -- Grand ma! epilepsy. Petit mal epilepsy. Myoclonic epilepsy. Atonic seizures. 2. Secondary epilepsy A. Local causes in the brain: l. Congenital: 2. Traumatic: cerebral palsy. a cause can be detected cerebral contusion or laceration. 3. Inflammatory: 4. Neoplastic: 5. Degenerative: 6. Vascular: encephalitis, brain tumours. mening1t1s, presenile dementia. brain abscess. stroke (especially hemon-hagic), hypertensive encephalopathy. B. General causes with secondary effects on the brain: I. Toxic: 2. Iatrogenic: 3. Metabolic: 4. Endocrinal: 5. Organ failure: 6. Heart disease: 7. Nutritional: - Alcohol, cocaine, lead. - Lidocaine, INH. - j glucose & ! glucose. - Hypoparathyroidism. - Hepatic failme. - Adam's Stoke's attacks. - Pellagra. - Botulism, tetanus. - Ambilhar, Amphetamine, Aminophylline. - j Ca & ! Ca. - Hype1thyroid crisis. - Renal failure. - Fallot's tetralogy. - j Na & ! Na. - Vitamin B6 deficiency. 8. Physical: 9. HYSTERICAL. - High fevers. - Heat stroke. 136 137 CLINICAL PICTURE 1. GENERALISED SEIZURES " Excessive electrical discharges from cortical neurons in BOTH hemispheres simultaneously " I. II. 1. Grand Mal Epile~: 1. Pre-ictal stage "attacks of tonic-clonic convulsions " (aura) It is a warning sign of a coming attack. It may be: • Somatic: • Psychic: • Autonomic: 2. Ictal stage Myoclonus, Hallucinations. Tachycardia, (seizure) Sudden loss of consciousness: Parasthesias. Sweating. for seconds to minutes. -- Tonic phase (few seconds) o The UL & LL: o o o o The HEAD: The JAWS: CYANOSIS: are extended. is retracted to one side & the eye balls rolled up. are firmly clenched, with biting of the TONGUE. due to impaired respiration. There may be incontinence of urine. Clonic phase (few minutes) o The UL & LL: o The HEAD: 3. Post-ictal stage - It may be: • Somatic: • Psychic: • Autonomic: Drug of choice: contract & relax repeatedly & rapidly. jerks forcibly. (sequelae) Todd's paralysis(< 24 hours, due to neuronal exhaustion). Confusion. Vomiting. Carbamazepine (Tegretol) or Phenytoin (Epanutin) Petit Mal Epilepsy: "attacks of loss of consciousness " " Absence " It starts in childhood & improves at puberty & usually disappears at the age of 20. 2. It is NOT PRECEEDED by aura & NOT FOLLOWED by sequelae. 3. It is usually PRECIPITATED by: hyperventilation 4. It is characterized by: or photic stimulation. sudden loss of consciousness of short duration (few seconds). 5. It may be associated with: • High frequency ( 50 attacks / day). • Falling to the ground without warning. • Jerky movements of the head & UL Drug of choice: (myoclonic petit mal). Valproate (Depakine) or Succinimide (Zarontin) 137 138 Ill. M oclonic Seizures: "attacks of involuntary clonic movements " - It is characterized by: sudden, jerky, shock-like INVOLUNTARY muscle contraction. • The jerks are bilateral contractions, mainly of the shoulders and arms. • However, some patients repmtjerking in the lower limbs, trunk, or head. - It may be of 2 types: - Occurs singly • Simple: • As a pait of: I Drug of choice: IV. Atonic seizures: (no loss of consciousness). - Grand mal epilepsy (aura). - Petit mal epilepsy. Valproate (Depakine) or Clonazepam (Rivotril) I - Transient attacks of brief loss of postural tone, often resulting in falls and injuries. 2. PARTIAL SEIZURES "Excessive electrical discharges from cmtical neurons in a ce1tain area in ONE hemisphere" A. Simple seizures: " No disturbance in consciousness " - The CP depends on the site of the hyperexcitable neurones in the cerebral cortex, whether in: "Motor area or Senso,y areas". 1. Motor fits: • Focal fits: • Motor jacksonian fits: 2. General Sensory fits: • Focal fits: • Sensory jacksonian fits: 3. Special Senso1y fits: • Visual hallucinations: • Auditory hallucinations: • Olfactory hallucinations: B. Complex seizures: - SITE: movement of part of a limb or the whole limb. movement of one side of the body (see before). parasthesia of part of a limb or the whole limb. parasthesia of one side of the body (see before). irritation of the visual sensory area. irritation of the auditory sensory area. initation of the uncus. " disturbance in consciousness " The hyperexcitable neurons are in the Temporal lobe "Temporal lobe epilepsy". - DURATION: The seizure lasts few seconds to few minutes. - The seizure starts with A ura, followed by A bsence, Automatism, Amnesia: 1. 2. 3. 4. A ura: A bsence: Automatism: A mnesia: Olfactory hallucinations, Deja-vu phenomenon, Sensation of fear. Absent patient with staring eyes (with no response to conversation). Involuntary Purposeless acts: motor ( eg, lip smacking, chewing) or verbal. No recalling of the seizure. 138 139 3. PARTIAL SEIZURES ~ GENERALISED SEIZURES " Partial seizures may spread to involve the whole brain .- secondarily generalised seizures " . HY-sterical epilepsY • Usually: • The cause: • Incidence: young neurotic Sj2 . psychological & there is no organic lesion. usually occurs in the presence of people. • It is associated with: • EEG: • It is not associated with: normal. • Missed ttt. • Menses. • Alkalosis. anxiety, palpitaion & hyperventilation. tongue biting or incontinence of urine. • Alcohol use & Drug abuse ( e.g. cocaine ). • S timulation by photons & Hyperventilation. • S leep deprivation & Stress & sudden withdrawal of antiepileptic drngs. INVESTIGATIONS 1. EEG: • It is the most specific test for epilepsy because it records the electrical activity of the brain. • It shows specific pattern: 2. LOCAL INVESTIGATIONS: "Epilepsy waves". "CT & MRI of the brain" • To identify or exclude a LOCAL CAUSE of seizures in the brain. 3. GENERAL INVESTIGATIONS: "Laboratory investigations" • To search for a GENERAL CAUSE of seizures, e.g. blood glucose. 139 140 TREATMENT A. General Measures: 1. 2. Moderation of the patient's physical activity. A void the precipitating factors ( Alcohol, hyperventilation, photic stimulation ...... ). 3. A ketogenic diet is encouraged because it will induce acidosis: - Acidosis is beneficial as it raises the threshold of stimulation of the brain cells. B. Specific Treatment: 2. 1. Treatment of the cause in secondary epilepsy. Anti-epileptic drugs: a) Always sta1t with one drug, then add another drug if there is no response. b) Always stop the drugs ONLY if: • The patient stays free of symptoms for at least 2 years. • The patient has a normal EEG. 3. Side effects of Anti-epileptic drugs: I . Skin rash. 2. 3. Bone marrow depression. Ataxia. Drug 1. Barbiturates (Pbenonobarbitone) 2. Hydantoin (Epanutin) 3. Carbamazepine 4. Clonazepam 5. Valproate 6. Succinamide ANTI-EPILEPTIC DRUGS NEW ANTI-EPILEPTIC DRUGS - These drugs are new dtugs that may be used in resistant seizures. 1. Lamotrigine: 200 - 400 mg/ day. 2. Felbamate: 3. Gabapentin: 400- 800 mg/ day. 600 - 1200 mg/ day. \ " General rules for use ": Dose 100-600 mg I day 100-600 mg / day 200-600 mg I day 2-6 mg I day 500-1500 mg I day 500-1000 mg / day Best indicated - Broad spectrum. - Not for petit mal. - Grand mal. - Motor Jacksonian fits. - Grand mal. - Motor Jacksonian fits. - Complex seizures. - Not for petit ma!. - Myoclonic. - Grand mat. - Broad spectrum. - Petit mat. 140 141 STATUS EPILEPTICUS DEFINITION - A medical emergency: 1. Repeated attacks of generalized convulsions, with lack of recove,y of consciousness, 2. Persistent attack of seizure lasting for at least 30 minutes. OR, - If the convulsions are not stopped rapidly, coma deepens & death may occur due to: heart failure or respiratory failure or brain damage or hyperpyrexia. - The most common causes are: sudden withdrawal of anti-epileptic drugs & stroke. TREATMENT A. General Measures: l. Take care of: " ABC " • Place the patient on the ground, to guard against falling from bed. • Mouth gag & 02 inhalation ( endo-tracheal intubation may be needed). • Record the vital signs regularly. 2. Take a sample of: - Venous blood: for the level of: - A.tierial blood: for the level of: 3. a nti-epileptic drugs, a lcohol. pH, p0 2, pC02, HC0 3. Give cerebral dehydrating measures: e.g. Frusemide, cone. Mannitol, Dexamethazone. B. Specific Treatment: - Phenytoin with diazepam (or clonazepam) immediately: 1. Phenytoin: 2. Diazepam: Clonazepam: seizures recur: 15 mg I Kg slow infusion. 5 mg slowly IV, to be repeated after 5 minutes if seizures recur: maximum dose: 20 mg. OR: 2 mg slowly IV, to be repeated after 5 minutes if maximum dose: 6 mg. - If seizures persist after 20 min. of Phenytoin & diazepam: 3. PHENOBARBITONE: - In resistant cases: 200 mg infusion. 4. GENERAL ANAESTHESIA: may be used.
Compact bone is composed of thin layers or lamellae of bone and form an osteon Organized lamellae greatly increases the strength of bone Lamellae also are organized as outer and inner circumferential lamellae Lacunae contain one osteocyte which interconnects with others through processes within canaliculi; osteocytes are supplied by vessels in the central canal Central canals communicate with marrow cavity, periosteum, and each other via transverse Volkmann’s (aka perforating) canals
Bone growth and remodeling New bone development is balanced with bone resorption Haversian systems are continually being replaced Bone is resorbed from one area and added to another to meet changing stresses placed on it (e.g., weight, posture, fractures) Normal growth dependent on sufficient proteins, minerals, vitamins (A, C, D) and influenced by hormones (growth, thyroid, estrogen/testosterone) Bone is capable of repair because it contains osteoprogenitor cells in the periosteum, endosteum, and bone marrow and is very well vascularized Metabolic role of bone (contains 99% of body’s total calcium in crystals) Transfer calcium from crystals to interstitial fluid and into blood Hormonal Parathyroid - stimulates osteoblasts to secrete osteoclast-stimulating factor thus promoting resorption Calcitonin - inhibits osteoclast activity
I beg to move, That this House welcomes the formation of a Government representing the united and inflexible resolve of the nation to prosecute the war with Germany to a victorious conclusion. On Friday evening last I received His Majesty's commission to form a new Administration. It as the evident wish and will of Parliament and the nation that this should be conceived on the broadest possible basis and that it should include all parties, both those who supported the late Government and also the parties of the Opposition. I have completed the most important part of this task. A War Cabinet has been formed of five Members, representing, with the Opposition Liberals, the unity of the nation. The three party Leaders have agreed to serve, either in the War Cabinet or in high executive office. The three Fighting Services have been filled. It was necessary that this should be done in one single day, on account of the extreme urgency and rigour of events. A number of other positions, key positions, were filled yesterday, and I am submitting a further list to His Majesty to-night. I hope to complete the appointment of the principal Ministers during to-morrow. the appointment of the other Ministers usually takes a little longer, but I trust that, when Parliament meets again, this part of my task will be completed, and that the administration will be complete in all respects. I considered it in the public interest to suggest that the House should be summoned to meet today. Mr. Speaker agreed, and took the necessary steps, in accordance with the powers conferred upon him by the Resolution of the House. At the end of the proceedings today, the Adjournment of the House will be proposed until Tuesday, 21st May, with, of course, provision for earlier meeting, if need be. The business to be considered during that week will be notified to Members at the earliest opportunity. I now invite the House, by the Motion which stands in my name, to record its approval of the steps taken and to declare its confidence in the new Government. To form an Administration of this scale and complexity is a serious undertaking in itself, but it must be remembered that we are in the preliminary stage of one of the greatest battles in history, that we are in action at many other points in Norway and in Holland, that we have to be prepared in the Mediterranean, that the air battle is continuous and that many preparations, such as have been indicated by my hon. Friend below the Gangway, have to be made here at home. In this crisis I hope I may be pardoned if I do not address the House at any length today. I hope that any of my friends and colleagues, or former colleagues, who are affected by the political reconstruction, will make allowance, all allowance, for any lack of ceremony with which it has been necessary to act. I would say to the House, as I said to those who have joined this government: "I have nothing to offer but blood, toil, tears and sweat." 2 We have before us an ordeal of the most grievous kind. We have before us many, many long months of struggle and of suffering. You ask, what is our policy? I can say: It is to wage war, by sea, land and air, with all our might and with all the strength that God can give us; to wage war against a monstrous tyranny, never surpassed in the dark, lamentable catalogue of human crime. That is our policy. You ask, what is our aim? I can answer in one word: It is victory, victory at all costs, victory in spite of all terror, victory, however long and hard the road may be; for without victory, there is no survival. Let that be realised; no survival for the British Empire, no survival for all that the British Empire has stood for, no survival for the urge and impulse of the ages, that mankind will move forward towards its goal. But I take up my task with buoyancy and hope. I feel sure that our cause will not be suffered to fail among men. At this time I feel entitled to claim the aid of all, and I say, "come then, let us go forward together with our united strength."
Multiplication and the Commutative Property
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