Sunday, February 17, 2019

Belimumab

Mechanism of Action :

Belimumab is an IgG1-lambda monoclonal antibody that prevents the survival of B lymphocytes by blocking the binding of soluble human B lymphocyte stimulator protein (BLyS) to receptors on B lymphocytes. This reduces the activity of B-cell mediated immunity and the autoimmune response.

Use :

Systemic lupus erythematosus: Treatment of adult patients with active, autoantibody-positive systemic lupus erythematosus (SLE) who are receiving standard therapy.

Limitations of use: Use is not recommended in patients with severe active lupus nephritis, severe active CNS lupus, or in combination with other biologics, including B-cell targeted therapies or intravenous (IV) cyclophosphamide.

Guttate Psoriasis

The papules and plaques of guttate psoriasis are usually less than 1 cm in diameter (giving rise to the name guttate, which means drop-like). The trunk and proximal extremities are the primary sites of involvement.

Guttate psoriasis typically occurs as an acute eruption in a child or young adult with no previous history of psoriasis. Less commonly, a guttate psoriatic flare occurs in a patient with preexisting psoriasis. There is a strong association between recent infection (usually streptococcal pharyngitis) and guttate psoriasis

Pustular Psoriasis

Pustular psoriasis — Pustular psoriasis is a form of psoriasis that can have life-threatening complications. The most severe variant (the von Zumbusch type of generalized pustular psoriasis) presents with the acute onset of widespread erythema, scaling, and sheets of superficial pustules . This form of psoriasis can be associated with malaise, fever, diarrhea, leukocytosis, and hypocalcemia. Renal, hepatic, or respiratory abnormalities and sepsis are potential complications.

Reported causes of pustular psoriasis include pregnancy (impetigo herpetiformis), infection, and the withdrawal of oral glucocorticoids. The term impetigo herpetiformis has been used to refer to pustular psoriasis of pregnancy.

Inverse Psoriasis

Inverse psoriasis — "Inverse psoriasis" refers to a presentation involving the intertriginous areas, including the inguinal, perineal, genital, intergluteal, axillary, or inframammary regions . This presentation is called "inverse" since it is the reverse of the typical presentation on extensor surfaces. This variant can easily be misdiagnosed as a fungal or bacterial infection since there is frequently no visible scaling.

Grading of Sacroiliitis on Imaging

Plain radiographs of the sacroiliac (SI) joints can be semiquantitatively graded based upon the presence of the characteristic radiographic findings :

●Grade 0: Normal .

●Grade 1: Suspicious changes .

●Grade 2: Minimal abnormality – Small localized areas with erosions or sclerosis, without alteration in the joint width . Erosions usually first appear on the iliac side.

●Grade 3: Unequivocal abnormality – Moderate or advanced sacroiliitis with erosions, evidence of sclerosis, widening, narrowing, or partial ankylosis .

●Grade 4: Severe abnormality – Total ankylosis

Classification Criteria for Axial Spondyloarthritis

Axial SpA — Classification criteria for axial SpA, including criteria for those without plain radiographic changes (nonradiographic axial SpA [nr-axSpA]) and with radiographic (radiographic axial SpA) changes of sacroiliitis, were based upon a large multicenter study [39]. In patients with a history of back pain of unknown origin, which was of at least three months' duration and which began before age 45, the classification criteria for axial SpA exhibited sensitivity of 83 percent and specificity of 84 percent [39]. This algorithm is as follows:

●The entry step is that the patient must have had back pain of any type for at least three months, and the age of onset must be less than 45 years.

●The second step consists of two arms that are evaluated separately based upon the presence either of sacroiliitis on imaging or of human leukocyte antigen (HLA)-B27:

•HLA-B27-positive patients – In patients who test positive for HLA-B27, at least two additional features of SpA from the list below are required for classifying a patient as having axial SpA (see 'SpA features' below)

•Sacroiliitis on imaging – In patients diagnosed with sacroiliitis based upon plain radiographs (structural changes) or magnetic resonance imaging (MRI) (subchondral bone marrow edema [BME]), at least one other feature of SpA from the list below should be present (see 'SpA features' below)

SpA features — The following are SpA features that contribute to the classification criteria for axial SpA (see 'Axial SpA' above):

●Inflammatory back pain – Several definitions for inflammatory back pain have been proposed. For classification purposes, inflammatory back pain can be defined as having at least four of the five following parameters [67]:

•Age of onset <40 years

•Insidious onset

•Improvement with exercise

•No improvement with rest

•Pain at night (with improvement upon arising)

●Other SpA features (each of equal weight) – Other SpA features include the presence of one or more of the non-spinal features noted below. The occurrence can be either before or at the time of evaluation for the following items listed: arthritis, heel enthesitis, uveitis, dactylitis, psoriasis, and inflammatory bowel disease. The features are:

•Arthritis – As diagnosed by a clinician

•Heel enthesitis – Spontaneous pain or tenderness at site of insertion of Achilles tendon or plantar fascia at the calcaneus diagnosed by a clinician

•Uveitis – Confirmed by an ophthalmologist

•Dactylitis – Diagnosed by a clinician

•Psoriasis – Diagnosed by a clinician

•Inflammatory bowel disease – Crohn disease or ulcerative colitis diagnosed by a clinician

•Good response to nonsteroidal antiinflammatory drugs (NSAIDs) – Within 24 to 48 hours

•Family history of SpA – Presence in first- or second-degree relatives of AS or acute anterior uveitis [37]

•Elevated C-reactive protein (CRP) – After exclusion of other causes for elevated CRP

Classification Criteria for Peripheral Spondyloarthritis

For classification as having peripheral SpA, the patient should NOT have concurrent inflammatory back pain. In that case, the axial SpA criteria should be used. However, inflammatory back pain in the past is considered as a contributing SpA feature. There are two steps in the algorithm for classifying peripheral SpA:

The entry step is that the patient should have, at the time of being seen, at least one of the following three findings:

●Arthritis

●Enthesitis (spontaneous pain or tenderness at any enthesis)

●Dactylitis

If the patient satisfies the entry criteria, the patient should show (or have had in the past) at least one of the features of SpA in Group A (below) or at least two of the features of SpA in group B (below):

●Group A SpA features:

•Uveitis – Confirmed by an ophthalmologist

•Psoriasis – Diagnosed by a clinician

•Crohn disease or ulcerative colitis – Diagnosed by a clinician

•Preceding infection – Urethritis/cervicitis or diarrhea within one month prior to onset of arthritis/enthesitis/dactylitis

•HLA-B27

•Sacroiliitis on imaging

●Group B SpA features:

•Arthritis – Diagnosed by a clinician

•Enthesitis – Diagnosed by a clinician

•Dactylitis – Diagnosed by a clinician

•Inflammatory back pain in the past

•Family history of SpA – Presence in first- or second-degree relatives of AS and acute uveitis

How to Define Inflammatory Back Pain

●Inflammatory back pain – Several criteria have been proposed for defining IBP ; we use the "ASAS [Assessment of SpondyloArthritis International Society] expert criteria" to identify patients with IBP . The criteria for IBP are met if at least four of the following five features are present and IBP is described as "suggested" in the presence of three of five features:

•Onset of back discomfort before the age of 40 years

•Insidious onset

•Improvement with exercise

•No improvement with rest

•Pain at night (with improvement upon arising)

The presence of four of the five features listed above has a sensitivity and specificity of 80 and 74 percent, respectively, for an inflammatory cause of the back pain among patients with chronic back pain of unclear origin and onset of the back pain at <45 years of age who were evaluated by local rheumatologists . However, when IBP is present, and considered independently of other factors, the probability of AS among patients with chronic back pain increases only from 5 percent to 14 to 16 percent .

Rhupus

Rhupus – The term rhupus has been used to describe patients with overlapping features of both SLE and RA. Whether rhupus is clinically and immunologically a distinct entity, a true overlap of SLE and RA, or a subset of patients with SLE remains a matter of debate. In addition to having serologies consistent with both SLE and RA, some patients classified as rhupus may have an erosive arthropathy that is atypical for SLE

Kikuchi's disease

●Kikuchi's disease – Kikuchi's disease is a benign and usually self-limited form of histiocytic-necrotizing lymphadenitis. Clinical features at presentation include lymphadenopathy as well as fever, myalgias, arthralgias, and, less commonly, hepatosplenomegaly. Associations with SLE have been reported, but the clinical course is usually favorable with spontaneous remission often occurring within four months. The diagnosis of Kikuchi's disease is based on a lymph node biopsy, which reveals a histiocytic cellular infiltrate.

Saturday, February 16, 2019

Psoriatic Arthritis

Diagnostic criteria for Psoriatic Arthritis :

●CASPAR criteria – The CASPAR study concluded that a patient with an inflammatory musculoskeletal disease (peripheral arthritis, spondylitis, or enthesitis) can be classified as having PsA if a total of at least three points is accumulated from the presence of the following list of features (each of which is assigned a certain number of points):

•Skin psoriasis that is:

-Present – two points, OR

-Previously present by history – one point, OR

-A family history of psoriasis, if the patient is not affected – one point

•Nail lesions (onycholysis, pitting) – one point

•Dactylitis (present or past, documented by a rheumatologist) – one point

•Negative rheumatoid factor (RF) – one point

•Juxtaarticular bone formation on radiographs (distinct from osteophytes) – one point

These classification criteria should facilitate studies in PsA and may function well in diagnosing PsA, given sensitivity and specificity in four studies, including two of early arthritis patients, ranging from 91 to 100 percent and 97 to 99 percent, respectively [90-94]. However, these criteria can only be applied to individuals who demonstrate evidence for inflammatory musculoskeletal disease (peripheral arthritis, axial disease, or enthesitis).

Rheumatology has a lot of Rheum (Room) for Internal Medicine.

Wednesday, February 13, 2019

Orotic aciduria


Hello Awesomites!
The question has helped me to learn the pyrimidine biosynthesis and urea cycle better. Felt like sharing it.
Let's get started.

OROTIC ACIDURIA= Excessive excretion of orotic acid in urine.
Orotic aciduria is caused by defect in either UMP synthase enzyme or Ornithine trancarbomylase (OTC) enzyme.

When UMP synthase is defective, orotic acid builds up and the synthesis of nucleic acid is impaired, leading to deficient hematopoiesis and growth. Orotic aciduria is associated with megaloblastic anemia due to decreased pyrimidine synthesis. This megaloblastic anemia is refractory to Vitamin B12, folic acid supplementation. This megaloblastic anemia present in infants.

SYMPTOMS
 Lethargy
 Fatigue
Incessant crying due to orotic acid crystals in ureter produces colicky pain
Growth retardation

SIGNS
Tachycardia and faint murmur due to hyperdynamic circulation in anemia.

LABORATORY INVESTIGATION:
Urine analysis show orotic acid crystals.
Peripheral blood smear show hypochromic megaloblastic anemia and hypersegmented neutrophils.
We can distinguish this increase in orotic acid secondary to OTC deficiency from hereditary orotic aciduria by looking at blood ammonia levels and the BUN (blood urea nitrogen).

HYPERAMMONAEMIA is present in OTC deficiency.

TREATMENT
Administration of uridine, which is converted to UMP, will bypass the metabolic block and provide the body with a source of pyrimidine. Uridine triacetate is a drug approved by FDA to be used in the treatment of hereditary orotic aciduria.

Have a great day.
-Upasana Y. :)

Sunday, February 10, 2019

RACE protocol in Atrial fibrillation.

Hello! This is a short post regarding RACE protocol. Before starting it, here are some high yielding points regarding Atrial fibrillation.

Most common cause of embolic stroke: Non rheumatic Atrial fibrillation.
Examination shows
1) Pulse: Fast
2) Rhythm: Irregular
3) Pulse deficit more than 10/ min is diagnostic of Atrial fibrillation.

Ecg finding:

1) No P wave
2) R-R interval keep varying

R. A. C. E. protocol is followed in treatment of the Atrial fibrillation.

1) Rate control :

Short acting beta blockers are given to decrease heart rate. Decreasing heart rate leads to increase filling time of the heart. This in turn leads to increase diastolic time. It Increases end diastolic volume, stroke volume, cardiac output and increase BP.

Beta blockers used: Intravenous Esmolol or Verapamil.

2)Anticoagulation:

Atrial fibrillation causes increase clot formation in heart. Clots can be detected by Transesophageal Echo.
Oral Dabigatran and Rivoroxaban given as a treatment. Earlier Warfarin was used but it is not used now due to tendency to form intracranial hemorrhage.

3) Rhythm control:

Intravenous Ibutilide (Class 3 antiarrythmic drug) given to control rhythm.
Chemicals cardioversion is drugs used to terminate ectopic foci.

4) Electrical cardioversion:

If chemical cardioversion fail, go for electrical cardioversion. In this technique patient is sedated with i.v. Propofol and DC shock of 200J biphasic is given.

That's it!

-Demotional bloke

Amiodarone and thyroid dysfunction

Amiodarone, a class III antiarrhythmic drug is associated with a number of side effects, including thyroid dysfunction (both hypo- and hyperthyroidism)

AMIODARONE INDUCED HYPERTHYROIDISM:
There are two types of amiodarone-induced thyrotoxicosis (AIT):
Type I: This type is typically seen in patients with preexisting multinodular goiter or latent Graves disease, the excess iodine from amIODarone results in enhanced thyroid hormone production.

Type II: In type II AIT there is destructive thyroiditis caused by the drug itself that results in excess release of T4 and T3(There is no hormone production). It typically occurs in patients without underlying thyroid disease.

AMIODARONE INDUCED HYPOTHYROIDISM:
1)Normally after exposure to an iodine load (eg, radiocontrast), iodine transport and thyroid hormone synthesis are transiently inhibited to prevent normal individuals from becoming hyperthyroid(the Wolff-Chaikoff effect). Normally patients escape this Wolff-Chaikoff effect and come back to normal within a few weeks, but patients with pre-existing subclinical thyroid disease fail to escape and develop hypothyroidism.

2)Amiodarone also inhibits 5'-deiodinase which is responsible for the peripheral conversion of T4 to T3. So there is a decrease in T3 production.

-Srikar Sama

Saturday, February 9, 2019

Wolff-Parkinson's White syndrome

Hello! This post is regarding WPW syndrome. It is an Autosomal recessive disorder.
In Normal heart, conduction is from SA node to cardiac myocytes via AV node and Purkinje fibers. In WPW syndrome, SA node transfers electric activity directly to cardiac myocytes. This transfer is done by 'Bundle of Kent'.  Since AV node is responsible for delay of the conduction in normal heart, skipping of the AV node causes excitation prior to the expected time. Hence low Cardiac output is sign in WPW syndrome.

Investigation: ECG done

Findings in ECG.

1) Since AV node is skipped in conduction, short P-R interval is seen.

2) q wave is responsible for conduction in septal region, here also it is skipped in ECG (Remember conduction directly from SA node to cardiac myocyte!). At the same time we see Delta waves.

What are Delta waves?
-Change in the upswinging of the 'R' wave.

3) PJ interval is normal

What is PJ interval?
-J point is the point where S wave ends.
Starting point of P wave to J point is called as PJ interval.

(Remember: Segments does not include waves, interval loves waves! Example: ST segment is from end of S to start of T wave)

Now, as we can figure it out PJ interval is PR + qRS
PR becomes shorter and qRS becomes  broader in WPW syndrome. qRS is broader because conduction of cardiac myocytes is slower than Purkinje fibers. (Hope you remember clue sentence here - conduction from SA node directly to cardiac myocytes!) Hence PJ interval is normal.

Treatment:

Flecainide given orally is DOC.
Treatment of choice is Radio-frequency ablation.

Sunday, January 27, 2019

Submission: Tips for Step 2 CK

Hello All,


I am currently preparing for my step 2 CS exam. I gave my step 2 CK in June 2018 and scored >250.

Here are the resources I used-

1) Onlinemeded lectures+MTB

2) U world Q bank

3) NBME /UWSA

Here is what I. Used to do-

Listen to Online meded lectures and take notes on MTB but I did not read them again. I just listened to OME lectures  2nd time while exercising.

I printed the pdf file circulating with UWorld tables and Followed listening lectures of online meded  with doing questions of Usmle World and taking notes on Tables file.

Then I used to revise whole system I did in the week on weekends

Initially I started with one system a week and in the end I did 2 systems in a week.

Some important points to note-

1) U world and Online meded are the basic resources. 

2) Listen to all the online meded lectures  before solving U world Qs. It helps alot and makes the process of going through Usmle world Qs a lot easier.

3) Memorise Usmle World tables on your tips. 

4) Every option of Usmle world Qs is important. Go through not only the right one but also the wrong options properly.

5) I used to give a NBME every 3-4 weeks to track my progress and gave UWSA in the end. I started with 200’s and went upto 250’s.

-Parneet kaur


Thursday, January 24, 2019

Mechanistic insights regarding Lesch-Nyhan syndrome

Lesch-Nyhan syndrome is characterized by choreoathetosis, dystonia, hyperuricemia, gout, self mutilatory behavior especially self biting of fingers and intellectual disability due to HGPRTase mutations.

So how does HGPRTase mutations actually cause dystonia and other extrapyramidal signs and symptoms?

1. For synthesis of dopamine tetrahydrobiopterin as a cofactor for tyrosine hydroxylase is required.
Tetrahydrobiopterin itself is derived by a series of reactions in which GTP cyclohydrolase is rate limiting enzyme.
Now HGPRTase deficiency causes depletion of GTP there by ultimately depleting tetrahydrobiopterin.

In fact GTP cyclohydrolase mutations are known to cause dopa responsive dystonia and phenotype similar to lesch-nyhan syndrome.

2. Secondly, dopamine receptors are linked to G-protein coupled receptors which alternate between GTP-GDP bound state, yet another link between GTP depletion and perturbation of dopamine signalling.

3. Adenosine deficiency due to reduction in salvage may adversely affect role of adenosine as neuroprotective agent.

Lastly, in lesch nyhan syndrome no characteristic imaging abnormalities are seen but reduced dendritic arborizations in caudate nucleus, putamen and nucleus accumbens is thought to underlie clinical manifestations.

Kirtan Patolia

Wednesday, January 16, 2019

Submission: Thyroid Acropachy

Let's go through quick review regarding Thyroid Acropachy! 

1)It is an uncommon finding of Graves disease.

2)It is a triad of clubbing+swelling of soft tissue of digits + periosteal reaction of extremity bones. 

3)It is usually associated with Thyroid Ophthalmopathy and Dermopathy.

X ray findings-Hands and feet involvement,soft tissue swelling, fluffy, asymmetric periosteal reaction

Skin biopsy- Fibroblast activation and GAG deposition.

Differentials: 

1)Pulmonary Osteoarthropathy-.

2)Symmetric periosteal reaction  -can involve long bones of forearms and legs

Treatment-
No Specific treatment available, Treatment directed at associated Ophthalmopathy and Dermopathy using Local corticosteroids and systemic immunosuppressive therapy.

By Parneet kaur



Tuesday, January 15, 2019

Cyanide poisoning

Cyanide is a mitochondrial toxin that causes death within minutes to hours of exposure.

PATHOPHYSIOLOGY:
1)Cyanide avidly binds to the ferric ion (Fe3+) of complex IV thus inhibiting the Electron transport chain.
2)The cell must then switch to anaerobic metabolism of glucose to generate ATP.Anaerobic metabolism leads to the formation of lactic acid and the development of metabolic acidosis.

TREATMENT:

1)Sodium nitrite and Amyl nitrite induce formation of methemoglobin. Cyanide has high affinity to metHb. This provides an attractive alternative binding site for cyanide which makes the ETC free.
2)Sodium thiosulfate can be given which converts cyanomethemoglobin to thiocyanate and metHb. Thiocyanate is then renally excreted and metHb can be converted back to normal Hb by using methylene blue.
3) Hydroxocobalamin, a precursor of vitamin B12, avidly binds to intracellular cyanide (with greater affinity than cytochrome oxidase) forming cyanocobalamin. This molecule is stable and readily excreted in the urine.

-Srikar Sama

Early morning workout and weight loss.

To reduce weight, early morning exercise is recommended but question is why?
Let's get back to basics before answering this question.

Body has three sources of blood glucose to maintain level uniformly.
1) Food.
2) Liver Glycogen.
3) ‎Gluconeogenesis.

Now, Liver Glycogen can provide energy for around 12-18 hours. Gluconeogenesis uses lots of energy to maintain blood glucose level. Between dinner and breakfast we have gap of around 12 hours. This mean before taking breakfast  liver glycogen stock is null! And body is using now gluconeogenesis to maintain blood glucose level and as you know it's going to take hell lots of ATPs to maintain it. Also, exercise uses lots of energy. Hence both in turn helps in reducing body weight.

What is wrong with evening workout?

Suppose a person has taken lunch around 2 pm and he's working out around 5-6 pm. Which stores will be used by body to maintain glucose level - food obviously! Hardly any Liver glycogen is used up. Also extra food will be stored.

That's all!

-Demotional bloke

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