Meniere's disease Second edition

History:

In late 19th century Prosper Meniere described a condition characterized by ear block, tinnitus, and vertigo. He even correctly identified the site of lesion to be labyrinth. It wont be a understatement to say that precious little has been added to the knowledge and understanding of the disorder since then. Prosper Meniere infact lived far ahead of his time. He was born in 1799 in France. In 1848 he began to translate the text book on hearing loss authored by Kramer. The book was written in German. This kindled his interest in otology.

In his classical seminal reports he goes on to describe a series of patients who presented with neural deafness, with hearing loss greater for low frequencies. Deafness was commonly unilateral in these patients. These patients usually  present with tinnitus, vertigo, nausea and vomiting. He reported that these patients had a normal ear drum. He also reported that these symptoms were completely reversible.

Download the e book from here:

http://ent-ebooks.wikidot.com/meniere-s-disease-second-edition

Open conservative partial laryngectomy

Introduction:
Organ preservation is becoming common these days. This applies
to larynx also. Laryngeal malignancies if identified early can be
effectively managed by conservative resection procedures of
larynx.
Advantages of organ preservation:
1. The patient need not live with the stigma of permanent
tracheostomy
2. Speech is preserved to the maximum extent
3. There is effective separation of air and food channels
4. Post operative recovery is very fast
5. Option of salvage total laryngectomy is still an option if the
conservative procedure fails

Read the complete e book from here

Vertical partial laryngectomy

Introduction:




Vertical partial Laryngectomy is a conservative laryngeal surgical procedure which involves removal of one half of the larynx while the other half is preserved. The dead space created after removal of one half of the larynx is closed using various flaps. This surgery was first proposed by Solis – Colen in 1869 to manage early malignant lesions involving vocal folds.


Indications:


1. Malignant tumors involving a single vocal cord early T1, T2 and select T3 lesions


2. Anterior commissure of the vocal cord should be free of the lesion






This surgery is not suitable for patients with growth vocal cord involving the anterior commissure and the opposite cord.


Advantages:


1. This is a conservative procedure where in patient is able to speak without the aid of prosthesis


2. Patient need not have a permanent tracheostome


3. Patient does not have any swallowing problems


You can view the video clipping of the surgery below:
 

Tumor Biology pertaining to laryngeal malignancy

Introduction:




Recent advances in tumor biology and genetics have increased our understanding of the basic mechanisms involved in the development of laryngeal malignancy and in predicting its clinical course. The following genes / enzymes may be of use in diagnosis & in predicting the prognosis of various malignant lesions involving the larynx.






Telomerase:


A brief introduction to this enzyme is a must. A telomere is a repeating DNA sequence at the end of the chromosome. They can reach a length of 15,000 base pairs. These telomeres function by preventing the chromosome from losing base pair sequence at their ends. They also prevent chromosomes from fusing with each other. Each time a cell undergoes division some amount of telomere is lost. When the telomere becomes too short the chromosome reaches a critical length and can no longer multiply. The cell which contains this critical length chromosome is considered to be too old and undergoes cell death (apoptosis). The length of the telomere is controlled by two mechanisms:


Erosion – Occurs each time a cell divides


Addition – This is determined by the activity of telomerase


Telomerase is an enzyme made of protein and RNA subunits. It elongates the chromosomes by adding TTAGGG sequences to the end of the existing chromosomes. This enzyme is found in abundance in fetal cells, germ cells and tumor cells. If this enzyme telomerase is activated in a cell it continues to grow and divide and is known as the “Immortal cell”.






This enzyme has been linked to carcinogenesis of larynx. The presence of this enzyme in the laryngeal cancer specimen serves as a marker in diagnosing persistent malignancy after irradiation. It is very helpful in picking up radio resistant cases / recurrent cases following irradiation.


PH-20:


This is a hyaluronidase usually expressed by malignant tissues. It is usually found to be elevated in metastatic lesions and hence can be used as a valuable tumor marker in identifying early nodal metastasis.


Herpes simplex virus DNA:


Polymerase chain reaction can be used to identify Herpes simplex virus DNA. This is found to be positive in nearly 75% of patients with laryngeal malignancies. This is due to the fact that this virus protein is a proved carcinogen.


Mutations involving gene p53:


Mutations involving gene p53 correlates with the clinical outcome of patients with laryngeal cancer.


Retinoblastoma protein:


Negative expression of this protein has been associated with higher likelihood of lymph node metastasis with significantly lower 5 years survival rates.






Cyclin D1:


This has been identified by immuohistochemical staining of paraffin embedded specimen. Low levels of cyclin D1 have been associated with radio resistance.