NEET MDS Synopsis
ENDOMETRIOSIS
Obstetrics and Gynaecology
ENDOMETRIOSIS
The proliferation and functioning of endometrial tissue outside of the uterine cavity
Incidence: - 15-30% of all premenopausal women, -mean age at presentation: 25-30 years
Etiology - unknown
theories
- retrograde menstruation theory of Sampson
- Mullerian metaplasia theory of Meyer
- endometriosis results from the metaplastic transformation of peritoneal mesothelium under the influence of certain unidentified stimuli
- lymphatic spread theory of Halban
- surgical transplantation
- deficiency of immune surveillance
Predisposing Factors
- nulliparity
- age > 25 years
- family history
- obstructive anomalies of genital tract
Sites of Occurrence
ovaries most common location, 60% of patients have ovarian involvement
broad ligament
peritoneal surface of the cul-de-sac (uterosacral ligaments)
rectosigmoid colon
appendix
Symptoms
there may be little correlation between the extent of disease and symptomatology
pelvic pain - due to swelling and bleeding of ectopic endometrium, unilateral if due to endometrioma
dysmenorrhea (secondary) - worsens with age, suprapubic and back pain often precede menstrual flow (24-48 hours) and continue throughout and after flow
infertility - 30-40% of patients with endometriosis will be infertile, 15-30% of those who are infertile will have endometriosis
dyspareunia on deep penetration
premenstrual and postmenstrual spotting
bladder symptoms - frequency, dysuria, hematuria
bowel symptoms - direct and indirect involvement diarrhea, constipation, pain and hematochezia
Diagnosis
truly a surgical diagnosis
history - cyclic symptoms - pelvic pain, dysmenorrhea, dyschezia
physical examination
- tender nodularity of uterine ligaments and cul-de-sac
- fixed retroversion of uterus
- firm, fixed adnexal mass (endometrioma)
laparoscopy
- dark blue or brownish-black implants (mulberry spots) on the uterosacral ligaments, cul-de-sac, or anywhere in the pelvis
- chocolate cysts in the ovaries (endometrioma)
- powder-burn lesions
- early white lesions and blebs
Treatment
pseudopregnancy - cyclic estrogen-progesterone (OCP) or medroxyprogesterone (Provera)
pseudomenopause - danazol (Danocrine) = weak androgen, s/e: weight gain, fluid retention, acne, or hirsutism, leuprolide (Lupron) = GnRH agonist (suppresses pituitary GnRH)
s/e: hot flashes, vaginal dryness, reduced libido, and osteoporosis with prolonged use .these can only be used short term because of osteoporotic potential
surgical
- laparoscopic resection and lasering of implants
- lysis of adhesions
- use of electrocautery
- unilateral salpingo-oophorectomy
- uterine suspension
- rarely total pelvic clean-out
- follow-up with 3 months of medical treatment
Vitamin B6: Pyridoxine, Pyridoxal, Pyridoxamine
Biochemistry
Vitamin B6: Pyridoxine, Pyridoxal, Pyridoxamine
Aids in protein metabolism and red blood cell formation. It is also involved in the body’s production of chemicals such as insulin and hemoglobin.
Vitamin B6 Deficiency Deficiency symptoms include skin disorders, dermatitis, cracks at corners of mouth, anemia, kidney stones, and nausea. A vitamin B6 deficiency in infants can cause mental confusion.
Malnutrition
General Pathology
Malnutrition
A. Marasmus - calorie malnutrition
A child with marasmus suffers growth retardation and loss of muscle. The loss of muscle mass results from catabolism and depletion of the somatic protein compartment.
With such losses of muscle and subcutaneous fat, the extremities are emaciated; by comparison, the head appears too large for the body. Anemia and manifestations of multivitamin deficiencies are present, and there is evidence of immune deficiency, particularly of T cell-mediated immunity.
B. Kwashiorkor - protein malnutrition - importance of protein quality as well as quantity
Marked protein deprivation is associated with severe loss of the visceral protein compartment, and the resultant hypoalbuminemia gives rise to generalized, or dependent, edema.
The weight of children with severe kwashiorkor is typically 60% to 80% of normal.
However, the true loss of weight is masked by the increased fluid retention (edema).
Children with kwashiorkor have characteristic skin lesions, with alternating zones of hyperpigmentation, areas of desquamation, and hypopigmentation, giving a "flaky paint" appearance.
Hair changes include overall loss of color or alternating bands of pale and darker hair, straightening, line texture, and loss of firm attachment to the scalp.
An enlarged, fatty liver (resulting from reduced synthesis of carrier proteins) and a tendency to develop early apathy, listlessness, and loss of appetite.
The bone marrow in both kwashiorkor and marasmus may be hypoplastic, mainly because of decreased numbers of red cell precursors. How much of this derangement is due to a deficiency of protein and folates or to reduced synthesis of transferrin and ceruloplasmin is uncertain. Thus, anemia is usually present, most often hypochromic microcytic anemia, but a concurrent deficiency of folates may lead to a mixed microcytic-macrocytic anemia.
C. Most cases of severe malnutrition are a combination of A and B usually characterized by:
• Failure of growth
• Behavioral changes
• Edema (kwashiorkor)
• Dermatosis
• Changes in hair
• Loss of appetite
• Liver enlargement
• Anemia
• Osteoporosis
Functions of the nervous system
PhysiologyFunctions of the nervous system:
1) Integration of body processes
2) Control of voluntary effectors (skeletal muscles), and mediation of voluntary reflexes.
3) Control of involuntary effectors ( smooth muscle, cardiac muscle, glands) and mediation of autonomic reflexes (heart rate, blood pressure, glandular secretion, etc.)
4) Response to stimuli
5) Responsible for conscious thought and perception, emotions, personality, the mind.
Behavioral Traits Associated with Parenting Styles
PedodonticsBehavioral Traits Associated with Parenting Styles
Various behavioral traits that can be associated with different parenting
styles:
Overprotective: Children may become dominant, shy,
submissive, or anxious due to excessive protection.
Overindulgent: This can lead to aggressive, demanding
behavior, and frequent temper tantrums, but may also foster affectionate
traits.
Rejecting: Children may appear well-behaved but can
struggle with cooperation, often being shy and crying easily.
Authoritarian: This style may result in aggressive,
overactive, and disobedient behavior, with children being evasive and
dawdling.
Valproic acid
Pharmacology
Valproic acid: broad spectrum (for most seizure types)
Mechanism: blocks Ca T currents in thalamic neurons (prevents reverberating activity in absence seizures), ↓ reactivation of Na channels (in tonic/clonic seizures; prolongs refractory periods of neurons, prevents high frequency cell firing)
Side effects: very low toxicity; common = anorexia, N/V; at high doses inhibits platelet function (bruising and gingival bleeding); rarely see idiosyncratic hepatotoxicity
Drug interactions: induces hepatic microsomal enzymes (↓ effectiveness of other drugs), binds tightly to plasma proteins so displaces other drugs
Sugar derivatives
Biochemistry
Sugar derivatives
Sugar alcohol - lacks an aldehyde or ketone. An example is ribitol.
Sugar acid - the aldehyde at C1, or the hydroxyl on the terminal carbon, is oxidized to a carboxylic acid. Examples are gluconic acid and glucuronic acid
Amino sugar - an amino group substitutes for one of the hydroxyls. An example is glucosamine. The amino group may be acetylated.
N-acetylneuraminate, (N-acetylneuraminic acid, also called sialic acid) is often found as a terminal residue of oligosaccharide chains of glycoproteins. Sialic acid imparts negative charge to glycoproteins, because its carboxyl group tends to dissociate a proton at physiological pH.
Glycosidic bonds: The anomeric hydroxyl group and a hydroxyl group of another sugar or some other compound can join together, splitting out water to form a glycosidic bond.
R-OH + HO-R' → R-O-R' + H2O
Disaccharides: Maltose, a cleavage product of starch, is a disaccharide with an α (1→4) glycosidic linkage between the C1 hydroxyl of one glucose and the C4 hydroxyl of a second glucose. Maltose is the α anomer, because the O at C1 points down from the ring.
Cellobiose, a product of cellulose breakdown, is the otherwise equivalent β anomer. The configuration at the anomeric C1 is β (O points up from the ring). The β(1→4) glycosidic linkage is represented as a "zig-zag" line, but one glucose residue is actually flipped over relative to the other.
Other disaccharides
Sucrose, common table sugar, has a glycosidic bond linking the anomeric hydroxyls of glucose and fructose. Because the configuration at the anomeric carbon of glucose is α (O points down from the ring), the linkage is designated α (1→2). The full name is α -D-glucopyranosyl-(1→2) β -D- fructopyranose.
Lactose, milk sugar, is composed of glucose and galactose with β (→4) linkage → the anomeric hydroxyl of galactose. Its full name is β -D-galactopyranosyl-(1→)- α -D-glucopyranose
Polysaccharides:
Plants store glucose as amylose or amylopectin, glucose polymers collectively called starch. Glucose storage in polymeric form minimizes osmotic effects
Amylose is a glucose polymer with α (1→4) glycosidic linkages, as represented above. The end of the polysaccharide with an anomeric carbon (C1) that is not involved in a glycosidic bond is called the reducing end
Amylopectin is a glucose polymer with mainly α (1→4) linkages, but it also has branches formed by α (1→6) linkages. The branches are generally longer than shown above. The branches produce a compact structure, and provide multiple chain ends at which enzymatic cleavage of the polymer can occur.
Glycogen, the glucose storage polymer in animals, is similar in structure to amylopectin. But glycogen has more α (1→6) branches. The highly branched structure permits rapid release of glucose from glycogen stores, e.g., in muscle cells during exercise. The ability to rapidly mobilize glucose is more essential to animals than to plants.
Cellulose, a major constituent of plant cell walls, consists of long linear chains of glucose, with β (1→4) linkages. Every other glucose in cellulose is flipped over, due to the β linkages. This promotes intrachain and interchain hydrogen bonds, as well as van der Waals interactions, that cause cellulose chains to be straight and rigid, and pack with a crystalline arrangement in thick bundles called microfibrils.
Glycosaminoglycans (mucopolysaccharides) are polymers of repeating disaccharides. Within the disaccharides, the sugars tend to be modified, with acidic groups, amino groups, sulfated hydroxyl and amino groups, etc. Glycosaminoglycans tend to be negatively charged, because of the prevalence of acidic groups.
Hyaluronate is a glycosaminoglycan with a repeating disaccharide consisting of two glucose derivatives, glucuronate (glucuronic acid) and N-acetylglucosamine. The glycosidic linkages are β(1→3) and β(1→4).
When covalently linked to specific core proteins, glycosaminoglycans form complexes called proteoglycans. Some proteoglycans of the extracellular matrix in turn link non-covalently to hyaluronate via protein domains called link modules. For example, in cartilage multiple copies of the aggrecan proteoglycan bind to an extended hyaluronate backbone to form a large complex Versican, another proteoglycan that binds to hyaluronate, is in the extracellular matrix of loose connective tissues.
Heparan sulfate is initially synthesized on a membrane-embedded core protein as a polymer of alternating glucuronate and N-acetylglucosamine residues. Later, in segments of the polymer, glucuronate residues may be converted to a sulfated sugar called iduronic acid, while N-acetylglucosamine residues may be deacetylated and/or sulfated
Heparin, a glycosaminoglycan found in granules of mast cells, has a structure similar to that of heparan sulfates, but is relatively highly sulfated.
Some cell surface heparan sulfate glycosaminoglycans remain covalently linked to core proteins embedded in the plasma membrane. Proteins involved in signaling and adhesion at the cell surface have been identified that recognize and bind segments of heparan sulfate chains having particular patterns of sulfation
Lectins are glycoproteins that recognize and bind to specific oligosaccharides.
Concanavalin A and wheat germ agglutinin are plant lectins that have been useful research tools
Mannan-binding lectin (MBL) is a glycoprotein found in blood plasma. It associates with cell surface carbohydrates of disease-causing microorganisms, promoting phagocytosis of these organisms as part of the immune response.
Selectins are integral proteins of the plasma membrane with lectin-like domains that protrude on the outer surface of mammalian cells. Selectins participate in cell-cell recognition and binding.
The Transition from the Deciduous to the Permanent Dentition.
Dental Anatomy
The Transition from the Deciduous to the Permanent Dentition.
1. The transition begins with the eruption of the four first permanent molars, and replacement of the lower deciduous central incisors by the permanent lower central incisors.
2. Complete resorption of the deciduous tooth roots permits exfoliation of that tooth and replacement by the permanent (successional) teeth
3. The mixed dentition exists from approximately age 6 years to approximately age 12 years. In contrast, the intact deciduous dentition is functional from age 2 - 2 /2 years of age to 6 years of age.
4. The enamel organ of each permanent anterior tooth is connected to the oral epithelium via a fibrous cord, the gubernaculum. The foramina through which it passes can be seen in youthful skulls
The deciduous second molars are particularly important. It is imperative that the deciduous second molars be preserved until their normal time of exfoliation. This prevent mesial migration of the first permanent molars.
Use a space maintainer in the event that a second deciduous molar is lost prematurely