Skip to main content


Showing posts from October, 2011

Antigenic Drift In Influenza Virus Infection

The influenza virus is a single-stranded RNA virus, bound by a nucleoprotein. This nucleoprotein determines the type of the virus whether it is virus type A, B or C. The spherical surface of the virus is a lipid bilayer containing the viral antigens. The viral antigens are "hemagglutinin and "neuraminidase". These two antigens determine the subtype of virus that is H1N1, H3N2 etc.(H stands for Hemagglutinin and N stands for Neuraminidase). When an individual gets an infection of Influenza virus, antibodies are formed against the neuraminidase and hemagglutinin antigens, which prevent future infections with the same subtype of influenza virus. But recurrent infection occurs through mutations of hemagglutinin and neuraminidase antigens that allow the virus to escape from the host antibodies, this phenomenon is called antigenic drift. Visit Home Page

Plexogenic Pulmonary Arteriopathy

Plexogenic Pulmonary Arteriopathy Plexogenic pulmonary arteriopathy is an arterial disease develop in individuals with long-standing pulmonary hypertension. In this disorder a tuft of capillary formations is present, producing a network or a web that spans the lumens of dilated thin-walled, small arteries Visit Home Page

Idiopathic Pulmonary Fibrosis (IPF)-Causes-Signs-Symptoms-Treatment

IPF is also called Cryptogenic fibrosing alveolitis . It is a pulmonary disorder of unknown aetiology characterized by diffuse interstitial pulmonary fibrosis. Males are affected more than are females and  2/3rd of the patients are older than 60 years of age at the time of presentation Diagnosis and Differential Diagnosis The histological pattern of fibrosis is referred to usual interstitial pneumonia (UIP) which is required for the diagnosis of IPF. Two other conditions also cause UIP, these are asbestosis and collagen vascular disease. Therefore these conditions must be ruled out before using the word "idiopathic". Pathogenesis: The exact cause of the fibrosis is unknown that's why it is called idiopathic. Morphologically, the pleural surfaces of the lung have the appearance of cobblestones because of retraction of scars along the interlobular septa. The cut surface shows fibrosis. The lower lobe is predominantly involved. The pattern of fibrosis is called usu

Chronic Bronchitis-Types-Causes-Clinical Signs and Symptoms

Chronic Bronchitis: Chronic bronchitis is a respiratory airway disorder and is defined as a persistent productive cough for at least 3 consecutive months in at least 2 consecutive years. Causes-Risk factors: 1. Smoking 2. people living in smog-ridden cities are at risk 3. Men are more at risk than females 4. Persistent chronic infections 5. Chronic asthma 6. Emphysema 7. Obstructive tumour Types of Chronic bronchitis: 1. Simple Chronic Bronchitis:      It is the most common form. The patients have a productive cough, but airflow is not obstructed. 2. Chronic asthmatic bronchitis:      Some patients with chronic bronchitis develop hyperresponsive airways, with intermittent bronchospasm and wheezing. This condition is called chronic asthmatic bronchitis. 3. Chronic obstructive bronchitis:      This is very common in heavy smokers. These patients develop chronic outflow obstruction (difficulty in exhaling air) usually with evidence of associated emphysema. Pathogene

Gastric Lymphoma - Causes - Risk Factors - Signs and Symptoms

Gastric Lymphoma Types There are two different types of lymphoma Part of systemic lymphoma with gastric involvement (32%) Primary involvement of the GIT (MALT Tumors) Occurrence: 10 – 20% of all lymphomas occur in the abdomen 50% of those are gastric in nature Risk factors Chronic H. Pylori infection (due to chronic stimulation of the MALT) In the early stages of disease Treatment of H. pylori, infection leads to regression of the disease Early stages also referred to as pseudo-lymphoma Indolent for long periods Low incidence of Spread to lymph nodes Involvement of bone marrow Therefore the much better prognosis Mostly involves the antrum At the time of presentation Larger than 10 cm (50%) More than 1 focus (25%) Ulcerated (30 – 50%) Pattern of metastasis similar to gastric carcinoma Signs and symptoms Occur late and are vague (dyspepsia, epigastric pain, hematemesis, melena &wt loss) Diagnosis based on histology Visit Home Page.

Hiatal Hernia-Types-Signs-Symptoms-Treatment-Complications

Hiatal Hernia There is an opening in the diaphragm which is known as oesophagal hiatus. Through this opening oesophagus enters from the chest cavity into the abdominal cavity. In hiatal hernia, the upper part of the stomach enters into the chest cavity through this opening. Types Of Hiatal Hernia: a. Axial or sliding hernia (95%) In this type, the stomach protrudes into the chest cavity only during swallowing, when swallowing is finished stomach falls back into the abdominal cavity. In the type, the junction of oesophagus and stomach and upper part of the stomach both protrude in to the chest cavity. During swallowing oesophagal muscles contract, oesophagus shortens in length, this pulls the stomach up into the chest cavity, which returns back when swallowing is over. b. Non-axial / paraesophageal / Rolling (5%)  In this type the gastro-oesophageal junction remains at it normal position, it does not enter the chest cavity. In this case, only the upper part of the stomach ente

Achalasia, Signs-Symptoms-Causes-Treatment-Complications

Achalasia, Signs, Symptoms, Causes, Treatment and Complications Of Achalasia. In Achalasia food can't pass through oesophagus properly and this causes progressive dysphagia (difficulty in swallowing)  It is associated with three major abnormalities: a. Aperistalsis. b. Partial or incomplete relaxation of the lower oesophagal sphincter. c. Increased tone of the LES. (Clinically there is progressive dysphagia.) Causes : Primary: (Failure of the inhibitory neuronal supply). Secondary (Chagas disease, Diabetic neuropathy, Polio, autoimmunity, amyloidosis, etc) Signs and Symptoms: 1. difficulty in swallowing 2. Heavy sensation in the chest 3. Chest pain 4. Regurgitation of food that is trapped in the oesophagus into the mouth 5. Coughing  6. Choking (food may enter the throat and block the tracheal air entrance) Treatment Laparoscopic myotomy and pneumatic balloon dilatation of lower oesophagal sphincter. Complications Of Achalasia: 1. Esophagitis 2. Oesophagal ulcer 3. Oes

Fetal Skull Diameters, Diameter Of Skull Of Fetus at Time Of Delivery,