Medicine Hack

PCI consists of balloon angioplasty followed by stenting. Balloon angioplasty expands the coronary lumen by stretching and tearing the atherosclerotic plaque and vessel wall. The atherosclerotic plaque is also redistributed a little along its longitudinal axis. Elastic recoil of the stretched vessel wall generally leaves a 30 to 35 percent residual diameter stenosis. Although stand-alone balloon angioplasty is rarely used other than for very small (<2.25 mm) vessels, balloon angioplasty remains integral to PCI for predilating lesions before stent placement, deploying coronary stents, and further expanding stents after deployment. Coronary stents are currently used in more than 90 percent of PCI procedures worldwide. Coronary stents lowers the incidence of vessel closure. Restenosis after coronary stent placement occurs in some patients due to excessive intimal hyperplasia within the stent. While bare metal coronary stents reduce the incidence of angiographic and clinica

Above is an electrophoresis of a patient suspected to have sickle cell disease. A blood sample was taken from him and the erythrocytes were separated. After lysis of the RBCs, hemoglobin was released and it was run on a polyacryamide gel. Electrophoresis was carried out and Western blot was performed to located the hemoglobin. The principle of electrophoresis is that the the more negatively charged particles move towards the positive pole and vice versa. In the case of sickle cell disease, glutamate is substituted by valine at the 6th position of the beta chain. This removes a negative charge from the chain and thus in the electric field the mutated chain will not move as far towards the positive pole as does the non-mutated chain. The interpretation is as follows: 1) X is a band that represents the mutated HbS. 2) Y is the normal Hb. 3) 1 is a carrier of HbS i.e. having one normal and one mutated chain. 4) 2 is a person who does not carry any mutant alleles. 5) 3 is a per

The shoulder joint is a synovial multi-axial spheroidal joint. It occurs between the roughly hemispherical head of the humerus and the shallow glenoid fossa of the scapula. Since there is no major bony constraint, the joint has 3 degrees of freedom. It is the most mobile joint of the body and allows all the movements shown above. The stability of the joint depends on the surrounding muscular and soft tissue envelope. It is one of the most frequently dislocated joints in the body.

The neck has 4 major compartments. 1) Vertebral compartment which is contains the cervical vertebrae and associated muscles of posture, 2) Visceral compartment which contains the thyroid, thymus and parathyroid as well as the esophagus and larynx, 3) 2 vascular compartments on both sides and these contain the major blood vessels and vagus nerve.

Narrow QRS complex     A.     Sinus tachycardia              B.     Paroxysmal supraventricular tachycardias (PSVTs)                      1.      Atrial tachycardias, including single-focus or multifocal (MAT) variants                        2.     AV nodal reentrant tachycardia (AVNRT)                       3.     AV reentrant tachycardia (AVRT) involving a bypass tract              C.     Atrial flutter              D.     Atrial fibrillation  Wide QRS complex     A.     Ventricular tachycardia                B.     SVT/AF or flutter, with aberrant ventricular conduction usually caused by either of the following:   1.     Bundle branch block patterns                          2.     Atrioventricular bypass tract (Wolff-Parkinson-White preexcitation patterns)  

Hemodialysis should be started when: 1) eGFR is < 6  mL/min/1.73  m 2 2) eGFR is < 15  mL/min/1.73  m 2   and patient is showing signs and symptoms of uremia, unable to control his hydration and blood pressure.  Cockcroft-Gault formula  is a very commonly used formula to get an estimate of the GFR. The unit for eGFR is  mL/min. The classification for stages of chronic kidney diseases  on the other hand is based on normalized eGFR i.e. the eGFR per 1.73  m 2  and the unit being mL/min/1.73   m 2 . Thus we also need to calculate the surface area of the patient's body. It is given by the formula as follows :  Body Surface Area ( m 2 ) = ( [Height(cm) x Weight(kg) ]/ 3600 )½ And the normalized eGFR ( mL/min/1.73   m 2 ) = (eGFR/BSA) x 1.73 A clinical example is given below.   A 45 year old man weighing 70 kg and 180 cm tall has been admitted to the hospital because of fluid overload. He has been treated for the past hours with diuretics but has not been im

A rise of some factor e.g. X of the internal environment is detected by the sensor. This information is relayed to the integrating center that causes the effector to produce a change in the opposite direction. The initial deviation is thus reversed, thus completing the negative feedback loop. The same holds true if the factor X is decreased. The integrating center detects a change from the set point and causes necessary effects to bring it back to normal. Below is a diagram that shows negative feedback loops maintain a state of dynamic consistency within the internal environment.  One such example is regulation of body temperature as explained in the link that follows.  Regulation of body temperature