jueves, 20 de junio de 2013

Cough


Cough:

  Cough is a protective reflex

  Expulsion of respiratory secretions or foreign particles from air passages

  Occurs due stimulation of mechano or chemo receptors in throat, respiratory passages or stretch receptors in the lungs.

Cough reflex:

  Pulmonary irritant receptors (cough receptors) in the epithelium of the respiratory tract are sensitive to both mechanical and chemical stimuli.

  The cough receptor are located mainly on the posterior wall of the trachea, pharynx, and at the main carina

  When these receptors triggered, impulses travel via the internal laryngeal nerve, to the medulla of the brain.

The cough center in the brain, produces cough which is necessary to remove the foreign material from the respiratory tract before it reaches the lungs.

Types of Cough:

  Useless(nonproductive) cough which should be suppressed

  Useful(productive) cough serves to drain the airway

  It’s suppression is not desirable , may be harmful

Etiology of cough:

  Upper/ Lower respiratory tract infection

  Smoking / Chronic Bronchitis

  Pulmonary tuberculosis

  Asthmatic cough

  Postnasal drip due to sinusitis

  Gastro esophageal reflux

  ACE inhibitor associated cough

Gestational Diabetes melliatus


GESTATIONAL DIABETES MELLITUS
(GDM):

It is a condition in which women without previously diagnosed diabetes exhibit high blood glucose levels during pregnancy (especially during third trimester). In other word, glucose intolerance that is first recognized during pregnancy is classified as GDM.

Pathophysiology of GDM:

       Pregnancy hormones and other factors are thought to interfere with the action of insulin

       Insulin resistance prevents glucose from entering the cells properly.

       As a result, glucose remains in the bloodstream, where glucose levels rise.

       More insulin is needed to overcome this resistance; about 1.5-2.5 times more insulin is produced than in a normal pregnancy.

Classification:

       According to White classification, GDM(type A) can be distinguished from diabetes that existed prior to pregnancy (pregestational diabetes).

These two groups are further subdivided according to their associated risks and therapy.

The two subtypes of gestational diabetes (diabetes which began during pregnancy) are:

       Type A1:

                Oral glucose tolerance test (OGTT)-Abnormal

                2-hour Postprandial Glucose-Normal

                Therapy-Diet modification

       Type A2:

                OGTT –Abnormal

                2-hour Postprandial Glucose level- Abnormal

                Therapy- Insulin

Renal tuberculosis


RENAL TUBERCULOSIS:

v  Tuberculosis  is a disease that normally affects the lungs but it can affect many other body organs such as the kidney

v  Common form of non pulmonary tuberculosis

v  Also called nephrotuberculosis , renal tuberculosis or tuberculosis of the kidney.

v  Tuberculosis of uro-genital organs is noted in 7% (apprx) of patients suffering from tuberculosis

Causative organism:

  Causative agent is most commonly is Mycobacterium tuberculosis but bovine tuberculosis may be involved.

  Other species within the genus Mycobacterium are free-living environmental saprophytes and are commonly found in water, hence it readily contaminate the lower urethra and external genitalia and, thus, often are isolated from urine samples( may cause disease in immunosuppressed individuals , including recipients of renal transplants )

Pathogenesis:

  If a tuberculous lesion in the lung gains access to the vascular system by erosion of the wall of a vessel, usually a vein, then emboli containing organisms may be disseminated throughout the body

   However, the bacilli have stringent growth requirements and generally tend to proliferate only in a small number of sites, including the kidney, epididymis, fallopian tube, bone marrow, and brain, particularly the hindbrain

  In most cases, at the time of presentation there is no evidence of active pulmonary disease suggesting that renal involvement occurs as a result of reactivation after a period of dormancy (a long latent period after the initial pulmonary tuberculosis infection)

  Following an initial, acute, inflammatory response with polymorphonuclear leukocytes, a chronic inflammatory process develops with macrophages and the subsequent development of granulomas with lymphocytes, and fibroblasts

Symptoms:

  No early symptoms (Many patients present with lower urinary symptoms typical of  bacterial cystitis)

  kidney inflammation

  Pyelonephritis

  Fever

  Chills ,Shivering

  Loss of appetite

  Weight loss

  Malaise

  Kidney pain

 

Swine flu


Swine Flu:

Swine influenza virus (referred to as SIV) refers to influenza cases that are caused by Orthomyxovirus endemic to pig populations. SIV strains isolated to date have been classified either as Influenza(virus C or one of the various subtypes of the genus Influenza virus A).  In the United States the H1N1 subtype was exclusively prevalent among swine populations before 1998; however, since late August 1998, H3N2 subtypes have been isolated from pigs. As of 2004, H3N2 virus isolates in US swine and turkey stocks were triple reassortants, containing genes from human (HA, NA, and PB1), swine (NS, NP, and M), and avian (PB2 and PA) lineages.

H1N1 VIRUS :

       Influenza A (H1N1) virus is a subtype of influenza A virus and the most common cause of influenza (flu) in humans.

       Some strains of H1N1 are endemic in humans and cause a small fraction of all influenza-like illness and a small fraction of all seasonal influenza

       H1N1 strains caused a few percent all human flu infections

       Other strains of H1N1 are endemic in pigs (swine influenza) and in birds (avian influenza).

It contains a combination of genes from swine, avian (bird), and human influenza viruses, it can be spread by eating pork products or being around pigs.

Breast Cancer


Breast Cancer:

Breast cancer is a cancer that starts in the cells of the breast. Worldwide, breast cancer is the second most common type of cancer after lung cancer and the fifth most common cause of cancer death. The phenomenon partly blamed on modern lifestyles in the Western world. Incidences of breast cancer in men are approximately 100 times less common than in women.

Pathology:

  The most common pathologic types of breast cancer are invasive ductal carcinoma, malignant cancer in the breast's ducts, and invasive lobular carcinoma, malignant cancer in the breast's lobule.

  Grade of tumor - The histological grade of a tumor is determined by a pathologist under a microscope.

   Protein & gene expression status - Currently, all breast cancers should be tested for expression, or detectable effect, of the estrogen receptor (ER), progesterone receptor (PR) and HER2/neu proteins. These tests are usually done by immuno histochemistry and are presented in a pathologist's report.

Signs and Symptoms:

  The first symptom, or subjective sign, of breast cancer is typically a lump that feels different than the surrounding breast tissue.

  changes in breast size or shape, skin dimpling, nipple inversion, or spontaneous single-nipple discharge

  . symptoms may include tingling, itching, increased sensitivity, burning, and pain. There may also be discharge from the nipple

Diagnosis:

       Breast cancer is diagnosed by the examination of surgically removed breast tissue

       Blood tumor marker testing is not routinely performed for the screening of breast cancer, and has poor performance characteristics for this purpose.

 

 

 

 

 

Medicinal and aromatic plant


Medicinal & Aromatic Plants

          History of herbal medicine is as older as human civilization.

          Plants were used in China, India, Egypt, Greece long before the beginning the Christian era.

          People of India, China have been using herbal drugs for over 5000 years.

          90% plants used in industries are collected from wild.

          About 800 species are used by industries but only about 20 species are under frequent cultivation

          Argentina, China, Hungary, India, Poland and Spain are examples of countries that cultivate some materials on a large scale.

          70% of plants involved destructive harvesting because of the parts like root, bark , stem, etc (plant can dye)

          World Health Organization (WHO) reported that, about 80 % of the population from developing country and 50-60 % from Developed country, still be used herbal medicine from primary health care  system

          The percentage of people using traditional medicines decreases in developed countries: 40-50 percent in Germany , 42 percent in the USA , 48 percent in Australia and 49 percent in France

Northern Blotting


Northern Blotting:

Northern blotting is an RNA blotting technique which was developed in 1977 by Alwine et al. at Stanford University.  It was named after the Southern blot technique which blots for DNA, invented by Edwin M. Southern in 1975. Northern analysis is still the gold-standard for the detection and quantization of mRNA levels. This is because northern blot analysis allows a direct comparison of the messenger RNA abundance between samples on a single membrane. I n northern blot the main difference between the other blotting techniques is that RNA is the factor being detected. Also, due to the fact that RNA is usually single-stranded, it creates complex secondary structures which affect its migration and hence denaturing conditions are used to run the gels. RNA is separated out by RNA gel electrophoresis (usually agarose gel electrophoresis), subsequent transfer to membrane, and hybridization with probe, and finally detection rad.

                                The northern blot is a technique used in molecular biology research to study gene expression by detection of RNA (or isolated mRNA) in a sample. It makes possible to observe cellular control over structure and function by determining the particular gene expression levels during differentiation, morphogenesis, as well as abnormal or diseased conditions. It also involves the use of electrophoresis to separate RNA samples by size and detection with a hybridization probe complementary to part of or the entire target sequence.

Procedure:

l  A general blotting procedure  starts with extraction of total RNA from a homogenized tissue sample.

l  The mRNA can then be isolated through the use of oligo (dT) cellulose chromatography to maintain only those RNAs with a poly(A) tail.

l   RNA samples are then separated by gel electrophoresis.

l  Since the gels are fragile and the probes are unable to enter the matrix, the RNA samples, now separated by size, are transferred to a nylon membrane through a capillary or vacuum blotting system.

l  A nylon membrane with a positive charge is the most effective for use in northern blotting since the negatively charged nucleic acids have a high affinity for them.

l   The transfer buffer used for the blotting usually contains formamide because it lowers the annealing temperature of the probe-RNA interaction preventing RNA degradation by high temperatures

l  .Once the RNA has been transferred to the membrane it is immobilized through covalent linkage to the membrane by UV light or heat.

l  After a probe has been labeled, it is hybridized to the RNA on the membrane

l  Experimental conditions that can affect the efficiency and specificity of hybridization include ionic strength, viscosity, duplex length, mismatched base pairs, and base composition.

 The hybrid signals are then detected by X-ray film and can be quantified by densitometry.

 

 

 

 

 

 

 

Antisence Technology


Antisense Technology:

  The  general concept for  antisense  technology  was created in the mid of 19th century(1978).

  Scientist coined the term “Antisense” because the mRNA sequence is known as the “sense” sequence. Since this technology blocks the mRNA it became known as “Antisense”.

      In principle, antisense technology is supposed to prevent protein production from a targeted gene.

Antisense oligonucleotides:

  Antisense  oligonucleotides are single strands of DNA  or RNA that are complimentary to the chosen sequence.

  In the case of antisense RNA they prevent protein translation of certain messenger RNA strands by binding to them.

  Antisense DNA can be used to target a specific, complimentary(coding or  non coding) RNA.

  If binding takes places this DNA/RNA hybrid can be degraded by the enzyme RNase H.

A case study in antisense technology;

The Flavr Savr Tomato:

Tomatoes allowed to completely ripen on the vine develop their full color, flavor and softness characteristics in great demand by consumers. But for shipping purposes, commercially grown tomatoes must be picked before they get too soft, resulting in hard, bland-tasting tomatoes at the market. The agricultural biotechnology company Calgene (California) used antisense technology to inhibit the production of the fruit-softening enzyme polygalacturonase which breaks down a cell wall polysaccharide. This resulted in a 90% reduction in polygalacturonase activity and a significantly longer ripening period. The “Flavr Savr” tomatoes could be left on the vine longer  to develop  color and flavor without getting as soft as normal tomatoes.  But they could still be shipped without being damaged and they would eventually soften at the market or at home. But, the Flavr Savr tomato  was only produced commercially for a few  years because the variety  used for genetic engineering  had inferior agronomic characteristics (too small, low yield). DNA Plant Technologies later introduced an antisense engineered tomato (“Endless Summer”) which inhibited ethylene production, but withdrew the product after a patent fight with Monsanto and take-over by another company.

 

 

 

 

 

 

miércoles, 19 de junio de 2013

Hypovolemic Shock

 Shock:

It is a situation in which a general disorder of blood flow exists where in tissue perfusion and oxygen delivery are reduced to a level below those required to meet metabolic demands despite the operation of various compensatory mechanism.
Shock is also the term given to the clinical condition in which the patient is pale, cold and sweaty, the pulse is rapid, of low volume and the arterial BP is relatively low, often less than 80 mmHg.

Role of Kidneys in Hypovolemic Shock:
 
Fall in MAP perfusing the kidneys and stimulation of sympathetic nerves, stimulate JGA leading to release of renin.
Renin converts Angiotensinogen to Angiotensin –I which is converted to Angiotensin- II.
Angiotensin- II causes
  i)    constriction of arterioles leading to increase ­ in TPR.
  ii)   release of aldosterone from adrenal cortex which helps in reabsorption of Na+ in the kidneys
  iii)  causes release of ADH which helps in the
            reabsorption of water from the kidney
  iv)  stimulates thirst center in the hypothalamus
           which increases water intake
     Overall effect is increase­ TPR, ­ increase BV, increase ­SV leading to an increase in BP
 
ØDecrease in MAP leads to ­ sympathetic discharge to kidneys which causes
   a) decrease in Renal blood flow (normal blood flow is 20-25% of CO)- diverting blood to increase circulating BV.
  b) decrease in GFR leading to decreased urine output
  c)  Stimulates JGA causing ­ secretion of
          renin.
Ø Increased release of erythropoietin
Overall effect is an­ increase in BV, ­increase in BP, increase in ­ RBC production.
 
 
Stages of Shock:
Stage I  - Stage of compensated, reversible hypotensive shock. This shock occurs when there is decrease in circulating blood volume by 10% or less.
Stage II  -  Stage of decompensated hypotension but potentially reversible shock. This stage of shock results when there is decrease in blood volume of not more than 35-40% and arterial BP does not fall below 50 mmHg.
Stage III  -  Irreversible stage of shock due to microcirculatory failure leading to cellular injury and death. In this stage arterial BP continues to fall to a critical level- usually about 45mmHg or below; at which vital organ perfusion is reduced and a vicious circle of deterioration of functions ensues i.e. shock it self causes shock.
 
Management Principles for Shock
“VIP” 
Ventilation:  To ensure adequate pulmonary exchange of oxygen and carbon dioxide.      Supplement oxygen , some may need mechanical ventilator.
Infusion:  To ensure adequate intravascular volume -  intravenous fluids, blood.
Pump:  To ensure cardiovascular competence:
      give Inotropes and vasopressors
                                   ­ 
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