Developmental stages of tooth.

1.Tooth bud
2.Oral epithelium
3.Ectomesenchyme

Bud stage.
-Enamel organ=central polygonal cells, peripheral low columnar cells.
-Dental papilla= forming pulp and dentin.
-Dental sac= ectomesenchyme that surrounds enamel organ and dental papilla.
= forming periodontal ligament and cementum.

Cap stage.
-Cap like shaped of enamel organ.
-Due to invagination on inner surface of tooth bud result from unequal division.
-Characterized by = outer and inner enamel epithelium(OEE, IEE), stellate reticulum.
o OEE= cuboidal cells, cover the convexity of cap.
o IEE= tall columnar cells, cover the concavity of cap.

= Basement membrane separate from dental papilla.
o Stellate reticulum

= cellular network of polygonal cells between IEE n OEE,
=separated by intercellular fluidàproteinatious fluid containing albumin
=f(x)=cushion like consistency to support n protects enamel forming cells.
o Dental papilla= the condensation of ectomesenchymal cells that covered by invaginated portion of IEE.
o Dental sac= condensation of surroundings areas of dental papilla n enamel organ resulting in fibre development.

1.Dental lamina
2.Dental sac or follicle
3.Outer dental epithelium
4.Stellate reticulum
5.Inner dental epithelium
6.Dental papilla
7.Enamel cord
8.Enamel navel
9.Blood vessel
10.Enamel niche
11.Successional dental lamina

Bell stage
- Characterized by = outer and inner enamel epithelium(OEE, IEE), stellate reticulum, stratum intermedium
o OEE
- cuboidal cells
- folded before enamel formation
- capillary network dev. From dental sac between folds.
- Provide blood supply to enamel organ.
- Dental papilla develops odontoblasts-->lay down dentin before first layer of enamel matrix.
o IEE= tall columnar cells à ameloblasts.
- F(x)=Influences underlying ectomesenchymal cells of dental papilla to form odontoblasts
o Stellate reticulum
- Continuous expansion in size due to increase intercellular fluid
- Before enamel formation, it collapse to decrease distance between ameloblast and capillary network.
o stratum intermedium
- layer of squamous cells btwn IEE and stellate reticulum.
- F(x)= essential for development, formation and calcification of enamel
o Dental papilla
- Covered by enamel organ.
- Its peripheral cells develop into odontoblast
- Cuboidal --> columnar-->secrete predentin

Advanced bell stage
- Future dentinoenamel junction- forms from boundary between IEE and odontoblast
- Hertwig’s epithelial root sheath (HERS) - forms from cervical portion of enamel organ.

p/s; tahu sikit2 tentang gigi kita..huhuhu

Development of tooth..

- Dental lamina; is a band of epithelium that has invaded the underlying ectomesenchyme along both the horseshoe-shaped future dental arches.
- Deciduous dentition developed from dental lamina (8th week)
- Successional lamina; lingual extension of dental lamina. Responsible for dev. Of permanent incisors, canines and premolars(5th month intrauterine life)
- Accessional lamina; distal extension of dental lamina. Responsible for dev. Of molars.

- "cell rest of serre" = remnants of dental lamina.

Staphylococcus aureus

(genus Staphylococcus)

Morphology
-Gram positive, non sporing, non motile cocci.
- Arranged in grape- like clusters (due to sequential division of bacteria in 3perpendicular planes with daughter cells in close proximity)

Cultural characteristics.
- Grow in ordinary media.
- Aerobic (facultatively anaerobic)
- Temp=10-42c
- pH7.4-7.6
- eg; nutrient agar, blood agar, MacConkey’s agar.

Biochemical reactions.
- Ferment mannitol
- Beta hemolysis on blood agar
- Gelatin liquefaction
- Phosphatase production
- Tellurite reduction

Antigenic structure
- Capsule = inhibit phagocytosis
- Peptidoglycans= activates complement, evokes production of inflammatory cytokines.
- Teichoic acid= antigenic determinant
- Protein A= when coated with IgG antiserum, will agglutinate if mixed with its corresponding antigen

Pathogenicity
- Due to production of toxin and enzymes.
o Toxins
§ Hemolysis
· Alpha lysine= lytic for rabbit erythrocyte, less active against human, causes injury to circulatory system and muscle tissues
· Beta lysine= llytic for sheep, not for human.
· Gamma lysine = acts on human, rabbit, sheep.
· Delta lysine= acts on human, rabbit, sheep.
§ Leucocidin= damages polymorphomuclear leucocytes and macrophages.
§ Enterotoxin= food poisioning, resistant to guts enzyme.
o Enzymes
§ Coagulase= clot human plasma, converts fibrinogen to fibrin.
-
- Dies at 62c for 30mins @ 80c for 1hr.
- Resistant to drying
- Local effect= inhibiting phagocytosis, form wall of fibrin clot around the lesion, pus is formed.
o Cutaneous infections= abcesses, boils, carbuncles.
o Deep infections= tonsillitis, osteomyelitis, sinusitis, pharyngitis, pneumonitis
o Food poisioning
o Toxic shock syndrome

Antibiotic sensitivity
- Resistance to panicilin= has panicilinase, reduction affinity to penicillin binding proteins

Laboratory diagnosis
- Collection of specimen
- Direct microscopy= gram staining-positive
- Culture
o Blood agar= colonies are circular, raised, opaque, produce golden yellow pigment(not diffusible into medium, beta hemolysis seen around colonies )
o Peptone water.

Treatment
- Benzyl Penicillin
- Cloxacillins
- Vancomycin

Coagulase negative staphylococci
- Form part of normal flora of the skin
- Opportunistic pathogen= infection in debilitated @ immunocompramised patients.
- Staph. Epidermis;
o Skin commensal
o Opportunistic pathogen in prosthetic devices
- Staph. Saprophyticus
o Causes urinary tract infection in young women
o Septicaemia and endocarditis in patients with cardiac surgery.

Corynebacterium diphtheriae.

(genus C. diphtheriae)

Morphology
-Gram positive, non acid fast, non sporing, non motile bacilli.
-Thin, slender, pleomorphic, non capsulated
-Show club shaped swelling (coryne) due to metachromatic granules at both ends.
-with Albert’s stain – green rod shaped resembling ‘L’ @ ‘V’ @ Chinese letter pattern @ cuneiform (due to incomplete separation of daughter cells after binary fusion) with bluish black metachromatic granules at the poles.

metachromatic granules
-also called babe Ernst granules @ volutin
-take up bluish purple colour of loeffler’s methylene blue
-composed of polymetaphosphates
-f(x)- energy storage

Cultural characteristics.
- Grow best in enriched media.
- Scanty in ordinary media.
- Aerobic (facultatively anaerobic)
- Temp=15-40c
- pH7.2
- eg; loeffler’s serum slope, tellurite blood agar.

Biochemical reactions.
- Ferment glucose n maltose
- Reduces nitrates to nitrites
- Not hydrolyse urea.

Toxin.
- Pathogenicity due to production of powerful exotoxin by its virulent strains.
- Action- inhibiting protein synthesis.
- Dies at 58c for 10mins @ 100c for 1min.
- Resistant to drying
- Susceptible to panicilin.
- Seen in children (2 – 10yrs)
- Incubation period =3 – 4 days
- Spreading= droplet
- Site= nasal, laryngeal, conjunctival , vulvovaginal.
- Local effect= toxin causes local necrotic changes and inflammatory reaction --> pseudomembrane
- Systemic effect= toxin diffuse into blood stream, have affinity towards cardiac muscle, adrenals, nerve ending.

Laboratory diagnosis
- Isolation organism;
o Collection of specimen
o Direct microscopy- gram stain n Albert’s stain
o Culture
§ loeffler’s serum slope= colonies are small, circular white @creamy
§ Potassium tellurite agar= black @ grey colonies
- Virulence test.

Diphtheroids
- Commensals corynebacteria
- Present in throat, skin.
- Few or no metachromatic granules
- Arranged parallel.

p/s; semoga sedikit sebanyak dapat membantu..insyaAllah

Sakit hati atau amaran?

Malam tadi seperti rutin biasa, aku dan kawan2 akan melepaskan tension di CCD(café coffee day). Mungkin tempat ini sahaja yg kelihatan seperti bukan di davangere..eheheh…

aku dan yg lain2 memparking motor betul2 dihadapan CCD yg mana ada pakguard yg menjaga. Namun syikin parkingkan motornye dihadapan kedai alatan tulis bersebelahan dengan CCD.
Ketika kami mahu pulang..

Terkejut!!
Tempat duduk motor syikin ditoreh!! Adakan panjang sejengkal setengah dan amat pasti guna pisau!!

Mula rasa tidak sedap hati dengan keganasan penduduk sini. Mungkinkah itu sebagai amaran atau hanya suka buat vandalism?(bukankah vandalism pada harta awam, jika harta perseorangan bagaimana pula?)

Amaran untuk pelajar Malaysia mungkin?

Namun cerita tidak berhenti disini. Pagi ini rupanya baru ku tahu yg motor pelajar lelaki mmg ada yg pernah dicalarkan. Malah pernah juga sticker di motor mereka sengaja dicabut dan ditampal terbalik.

Hingga kini masih belum tahu siapa pelaku.

Mungkin pelajar2 tempatan.

Mungkin juga pekerja2.

Sakit hati atau amaran?

Mungkinkah akan berlaku kes lebih keras drpd ini?
Nauzubillah…Allah mohon lindungi kami..

p/s; tolong lebih berhati2 selepas ini. Kita hanya ada kita disini..

Pura rasa..

Perlu ikut rasa hati atau pura rasa?

Jika hanya dengan sekelumit pura mampu mengulas senyum bibir teman, mengapa tidak?
Jika hanya dengan sekelumit pura mampu memutar mood teman, mengapa tidak?
Jika hanya dengan sekelumit pura mampu jadi lebih mesra dengan teman, mengapa tidak?
Jika hanya dengan sekelumit pura mampu menjadi teman yg lebih baik, mengapa tidak?
Jika hanya dengan sekelumit pura mampu menyedapkan hati teman, mengapa tidak?
Jika hanya dengan sekelumit pura mampu mengubah situasi, mengapa tidak?



p/s; kadang pura rasa mungkin lebih baik drpd rasa diri..hum..

Give n take..

Sangat perlu dalam hubungan.

Namun mungkin ada yg lebih suka memberi drpd menerima dan ada juga lebih suka menerima drpd memberi. Lebih suka memberi tidak bererti tidak suka menerima dan lebih suka menerima tidak bermakna tidak suka memberi.

Dusta bagi manusia yg lagaknya hanya suka memberi sahaja dan tidak suka menerima. Pasti ada walau sepicing untuk terkadang menjadi penerima pula. Tika ini siapa mahu memberi?

p/s; sedar kurang pandai memberi lebih maka layak terima yang dapat-dapat sahaja..

sangka buruk..

"wahai orang-orang yg beriman! jauhilah banyak dari prasangka, sesungguhnya sebahagian prasangka itu dosa, dan janganlah kamu mencari-cari kesalahan orang lain, dan janganlah di anara kamu yang menggunjing kesalahan orang lain. apakah antara kamu yang suka memakan daging saudaranya yang sudah mati? tentu kamu merasa jijik. dan bertaqwalah kepada Allah, sungguh Allah Maha Penerima Taubat, Maha Penyayang" (49:12)