Dv's Random Notes 1

VESICOURETERIC REFLUX
International classification
- 1- Partial filling of an undilated ureter
- 2- Total filling of an undilated ureter
- 3 – Dilated calyces but fornices sharp
- 4 – Blunted fornices and degree of dilatation greater
- 5 - Massive hydronephrosis and tortuosity of the ureters
INDICATIONS FOR SURGERY IN VUR
- 1. Break through infections
- 2. Anatomic abnormalities at the junction
- 3. 4&5 reflux in lower pole of duplex system
- 4. Persistent reflux in adolescence
- 5. Grade 5 reflux
- 6. Noncompliance with medical management
- 7. Associated with ureteral obstruction
Hypospadias
- Rx MAGPI
- Duckett’s Chordee correction.
Cerebral Blood Flow & Its Regulation
- Inhaled nitrous oxide (N2O) (Kety method). The average cerebral blood flow in young adults is 54 mL/100 g/min. The average adult brain weighs about 1400 g, so the flow for the whole brain is about 756 mL/min. In resting humans, the average blood flow in gray matter is 69 mL/100 g/min compared with 28 mL/ 100 g/min in white matter.
- Because brain tissue and spinal fluid are essentially incompressible, the volume of blood, spinal fluid, and brain in the cranium at any time must be relatively constant (Monro–Kellie doctrine).
- In the brain, auto regulation maintains a normal cerebral blood flow at arterial pressures of 65–140 mm Hg.
- O2 consumption by the human brain (cerebral metabolic rate for O2, CMRO2) averages about 3.5 mL/ 100 g of brain/min (49 mL/min for the whole brain) in an adult. This figure represents approximately 20% of the total body resting O2 consumption.
- Glucose enters the brain via GLUT 1 in cerebral capillaries.
- Blood Flow in Various Parts of the Brain – Best is P.E.T (2 Deoxy Glucose).
- CPP = MAP – CVP/ICP (whichever is higher), (Normal CPP 80-100 mmHg, ICP <10 mmHg).
- Most important extrinsic influence on CPP is Arterial pCO2.
- Cerebral Blood Flow changes by 5-7 % with 10C change of temperature.
The Renin–Angiotensin System
- Renin is an aspartyl protease, contains 340 AA, t ½ < 80 min.
- After Nephrectomy the prorenin levels may actually rise (from ovaries), but rennin falls to 0.
- Angiotensinogen is found in the 2-globulin fraction.
- Angiotensinogen -> AT-I (decapeptide) -> (ACE) AT-II (octapeptide) in Lungs. ACE is a dipeptidyl carboxypeptidase that splits off histidyl - leucine from the physiologically inactive angiotensin I. AT II t ½ 1-2 minutes. The normal PRA in supine subjects eating a normal amount of sodium is approximately 1 ng of angiotensin I generated /mL/hr. The plasma angiotensin II concentration in such subjects is about 25 pg/mL (approximately 25 pmol/L).
- Dry Cough in ACEI is d/t increased Bradykinin.
- AT1 receptors are serpentine receptors coupled by a G protein (Gq).
- 1. JG cells (granular cells) - in the media of the afferent arterioles – intra renal pressure sensor, 2. Agranular lacis cells those are located in the junction between the afferent and efferent arterioles in the mesangium, 3. Macula densa (part of tubule – start of DCT, senses Na+) All 3 constitutes JGA.
- GOLDBLATT Hypertension – Syn. Renal Hypertension – decreased blood supply to one kidney -> increased renin.
Gilbert's syndrome - mutation in the UGT1A1 gene promoter- reduced UGT1A1- ADR with 1. Tranilast (in post CABG patients to prevent restenosis), 2. Irinotecan, a prodrug, SN-38 active metabolite, potent Topoisomerase Inhibitor - Leucopenia, Neutropenia and Diarrhoea
Digenic inheritance - retinitis Pigmentosa. XLD – Incontinentia Pigmentosa – lethal to males.
Teratogenicity:
- 1. Lithium – Ebstein’s Anomaly.
- 2. Pencillamine – Cutis Laxa.
- 3. Misoprostol – Mobius Sequence.
- 4. Warfarin – Chondrodysplasia
Free Water Clearance = CH2O = V x [1 – Uosm/Posm], V is Urine production in mL/min.
Atrial Natriuretic peptide is degraded by Neutral Endopeptidase.

ORTHOPAEDICS
· Radiological evidence of Callus formation: 3 weeks after the fracture.
· ‘Creeping substitution’ is seen in healing of cancellous bone.
· Hormones increasing Callus formation: Calcitonin and GH. (Cortisone decrease callus).
· Thyroxine/PTH: increase remodeling.
· Wolf”s Law – “Increased callus formation when there is increased stress”.
· Healing time of a fracture can be predicted by using Perkin’s Time table
· Low ultrasound inc. Ca2+ incorporation, results in stiffer, stronger callus, Accelerated enchondral ossification.
· Member of TGF- family which stimulates mesenchymal cells into osteochondroblastic lineage - Bone Morphogenic Protein (Urist 1965). BMP 2,4 and 7 play a crucial role in bone healing.
· Classification for ankle fractures –LAUGE HANSEN CLASSIFICATION, DANIS-WEBER CLASSIFICATION amplified by A.O (based on level of fracture in relation to syndesmosis).
· Special X Ray taken for Ankle injuries: Internal Rotation of 15-200. MORTISE view.
· MAISONNEUVE FRACTURE: special type of ankle, a spiral fracture around the neck of fibula above the level of syndesmosis -which need not be internally fixed.
· Enchondroma, Osteochondroma ( Exostosis )