NEET MDS Synopsis
Causes of sudden loss of consciousness and collapse
General Medicine
• Simple faint
• Diabetic collapse secondary to hypoglycaemia
• Epileptic seizure
• Anaphylaxis
• Cardiac arrest
• Stroke
• Adrenal crisis
Casting of glass or ceramic
Dental Materials
Casting of glass or ceramic
A castable ceramic is prepared in a similar manner as metal cast preparation .
Glass is heated to 1360 degrees & then cast.
Phosphate bonded investments are used for this purpose .
Nalidixic acid
Pharmacology
Nalidixic acid:
Nalidixic acid is the basis for quinolone antibiotics. It acts bacteriostatically (that is, it inhibits growth and reproduction) or bactericidally (it kills them) on both Gram positive and Gram negative bacteria, depending on the concentration. It is especially used in treating urinary tract infections, caused for example by Escherichia coli, Proteus, Enterobacter and Klebsiella.
Precipitation Reaction
General Microbiology
Precipitation Reaction
This reaction takes place only when antigen is in soluble form. Such an antigen when
comes in contact with specific antibody in a suitable medium results into formation of an insoluble complex which precipitates. This precipitate usually settles down at the bottom of the tube. If it fails to sediment and remains suspended as floccules the reaction is known as flocculation. Precipitation also requires optimal concentration of NaCl, suitable temperature and appropriate pH.
Zone Phenomenon
Precipitation occurs most rapidly and abundantly when antigen and antibody are in optimal proportions or equivalent ratio. This is also known as zone of equivalence. When antibody is in great excess, lot of antibody remains uncombined. This is called zone of antibody excess or prozone. Similarly a zone of antigen excess occurs in which all antibody has combined with antigen and additional uncombined antigen is present.
Applications of Precipitation Reactions
Both qualitative determination as well as quantitative estimation of antigen and antibody can be performed with precipitation tests. Detection of antigens has been found to be more sensitive.
Agglutination
In agglutination reaction the antigen is a part of the surface of some particulate material such as erythrocyte, bacterium or an inorganic particle e.g. polystyrene latex which has been coated with antigen. Antibody added to a suspension of such particles combines with the surface antigen and links them together to form clearly visible aggregate which is called as agglutination.
Application of precipitation reactions
Precipitation reaction Example
Ring test Typing of streptococci, Typing of pneumococci
Slide test (flocculation) VDRL test
Tube test (flocculation) Kahn test
Immunodiffusion Eleks test
Immunoelectrophoresis Detection Of HBsAg, Cryptococcal antigen in CSF
Bias in Public Health Dentistry
Public Health DentistryHere are some common types of bias encountered in public health dentistry,
along with their implications:
1. Selection Bias
Description: This occurs when the individuals included in a
study are not representative of the larger population. This can happen due to
non-random sampling methods or when certain groups are more likely to be
included than others.
Implications:
If a study on dental care access only includes patients from a specific
clinic, the results may not be generalizable to the broader community.
Selection bias can lead to over- or underestimation of the prevalence of
dental diseases or the effectiveness of interventions.
2. Information Bias
Description: This type of bias arises from inaccuracies in
the data collected, whether through measurement errors, misclassification, or
recall bias.
Implications:
Recall Bias: Patients may not accurately remember their
dental history or behaviors, leading to incorrect data. For example,
individuals may underestimate their sugar intake when reporting dietary
habits.
Misclassification: If dental conditions are
misdiagnosed or misreported, it can skew the results of a study assessing
the effectiveness of a treatment.
3. Observer Bias
Description: This occurs when the researcher’s expectations
or knowledge influence the data collection or interpretation process.
Implications:
If a dentist conducting a study on a new treatment is aware of which
patients received the treatment versus a placebo, their assessment of
outcomes may be biased.
Observer bias can lead to inflated estimates of treatment effectiveness
or misinterpretation of results.
4. Confounding Bias
Description: Confounding occurs when an outside variable is
associated with both the exposure and the outcome, leading to a false
association between them.
Implications:
For example, if a study finds that individuals with poor oral hygiene
have higher rates of cardiovascular disease, it may be confounded by
lifestyle factors such as smoking or diet, which are related to both oral
health and cardiovascular health.
Failing to control for confounding variables can lead to misleading
conclusions about the relationship between dental practices and health
outcomes.
5. Publication Bias
Description: This bias occurs when studies with positive or
significant results are more likely to be published than those with negative or
inconclusive results.
Implications:
If only studies showing the effectiveness of a new dental intervention
are published, the overall understanding of its efficacy may be skewed.
Publication bias can lead to an overestimation of the benefits of
certain treatments or interventions in the literature.
6. Survivorship Bias
Description: This bias occurs when only those who have
"survived" a particular process are considered, ignoring those who did not.
Implications:
In dental research, if a study only includes patients who completed a
treatment program, it may overlook those who dropped out due to adverse
effects or lack of effectiveness, leading to an overly positive assessment
of the treatment.
7. Attrition Bias
Description: This occurs when participants drop out of a
study over time, and the reasons for their dropout are related to the treatment
or outcome.
Implications:
If patients with poor outcomes are more likely to drop out of a study
evaluating a dental intervention, the final results may show a more
favorable outcome than is truly the case.
Addressing Bias in Public Health Dentistry
To minimize bias in public health dentistry research, several strategies can
be employed:
Random Sampling: Use random sampling methods to ensure
that the sample is representative of the population.
Blinding: Implement blinding techniques to reduce
observer bias, where researchers and participants are unaware of group
assignments.
Standardized Data Collection: Use standardized
protocols for data collection to minimize information bias.
Statistical Control: Employ statistical methods to
control for confounding variables in the analysis.
Transparency in Reporting: Encourage the publication of
all research findings, regardless of the results, to combat publication
bias.
Characteristics of Opioid Receptors
Pharmacology
Characteristics of Opioid Receptors
mu1
Agonists : morphine phenylpiperidines
Actions: analgesia bradycardia sedation
mu2
Agonists : morphine phenylpiperidines
Actions: respiratory depression euphoria physical dependence
delta
Actions: analgesia-weak, respiratory depression
kappa
Agonists: ketocyclazocine dynorphin nalbuphine butorphanol
Actions: analgesia-weak respiratory depression sedation
Sigma
Agonists: pentazocine
Action: dysphoria -delerium hallucinations tachycardia hypertension
epsilon:
Agonists: endorphin
Actions: stress response acupuncture
Hepatic failure
General Pathology
Hepatic failure
Etiology. Chronic hepatic disease (e.g., chronic active hepatitis or alcoholic cirrhosis) is the most common cause of hepatic failure although acute liver disease may also be responsible.
- Widespread liver necrosis may be seen with carbon tetrachloride and acetaminophen toxicity. Widespread steatosis is seen in Reye's syndrome, a cause of acute liver failure most often seen in children with a recent history of aspirin ingestion for an unrelated viral illness.
- Massive necrosis may also be seen in acute viral hepatitis, after certain anesthetic agents, and in shock from any cause.
Clinical features. Hepatic failure causes jaundice, musty odor of breath and urine, encephalopathy, renal failure (either by simultaneous toxicity to the liver and kidneys or the hepatorerial syndrome), palmar erythema, spider angiomas, gynecomastia , testicular atrophy
Embrasures
PeriodontologyClassification of Embrasures
Type I Embrasures:
Description: These are characterized by the
presence of interdental papillae that completely fill the embrasure
space, with no gingival recession.
Recommended Cleaning Device:
Dental Floss: Dental floss is most effective in
cleaning Type I embrasures. It can effectively remove plaque and
debris from the tight spaces between teeth.
Type II Embrasures:
Description: These embrasures have larger spaces
due to some loss of attachment, but the interdental papillae are still
present.
Recommended Cleaning Device:
Interproximal Brush: For Type II embrasures,
interproximal brushes are recommended. These brushes have bristles
that can effectively clean around the exposed root surfaces and
between teeth, providing better plaque removal than dental floss in
these larger spaces.
Type III Embrasures:
Description: These spaces occur when there is
significant loss of attachment, resulting in the absence of interdental
papillae.
Recommended Cleaning Device:
Single Tufted Brushes: Single tufted brushes
(also known as end-tuft brushes) are ideal for cleaning Type III
embrasures. They can reach areas that are difficult to access with
traditional floss or brushes, effectively cleaning the exposed root
surfaces and the surrounding areas.