CONGESTION

Congestion or hyperaemia means an increase in the content of blood in an organ. It may be :

A. Active - due to increased arterial flow to the organ with dilatation of micro vessels as in

• Inflammation.
• Increased metabolic activity.
• Neurogenic blushing.

B. Passive - due to decreased venous drainage resulting in pooling of blood. There is always an associated element of oedema.

Str. agalactiae

β-hemolytic, with its capsule being the major virulence factor.  Capsule inhibits phagocytosis and complement activation.  The CAMP factor (a hemolysin) is another virulence factor.

Group B strep are normally found in GI tracts and vaginas. 

Major disease is neonatal sepsis/meningitis after passage through infected birth canal.  May lead to meningitis, and CNS damage is high.  Mothers colonized with Group B strep should be treated pre-delivery.

Pulmonary Hypertension 

Sustained elevation of mean pulmonary arterial pressure.

Pathogenesis 
Elevated pressure, through endothelial cell dysfunction, produces structural changes in the pulmonary vasculature. These changes ultimately decrease pulmonary blood flow and stress the heart to the point of failure. Based on etiology, pulmonary hypertension is divided into two categories.

Primary (idiopathic): The cause is unknown.
Secondary: The hypertension is secondary to a variety of conditions which increase pulmonary blood flow or increase resistance to blood flow. Example: Interstitial fibrosis.
Pathology 
The changes involve large and small pulmonary blood vessels and range from mild to severe. The major changes include atherosclerosis, striking medial hypertrophy and intimal fibrosis of small arteries and arterioles, and plexogenic arteriopathy. Refer to Figure 15-7 in your textbook.

Pathophysiology 
Dyspnea and fatigue eventually give way to irreversible respiratory insufficiency, cyanosis and cor pulmonale.

Streptococcal pharyngitis:

A disease of young people, enlarged lymphoid nodules and keratin plugs in the tonsillar pits is seen Complications include retro-pharyngeal abscess (quinsy)

Cellulitis of the deep tissues of the neck is Ludwig's angina

Scarlet fever ("scarlatina") is a strep throat caused by a streptococcus with the gene to make one of the erythrogenic toxins, Patients have a rash with PMNs

Streptococcal skin infections (Impetigo)

Erysipelas is a severe skin infection caused by group A strep; geographic of red, thickened, indurated areas of the skin are characteristic. Unlike staph infections, there is usually little or no tissue necrosis

Post-streptococcal hypersensitivity diseases include rheumatic fever, post-streptococcal glomerulonephritis, and some cases of erythema nodosum

Hyperthyroidism 

Hyperthyroidism (Thyrotoxicosis) is a hypermetabolic state caused by elevated circulating levels of free T3 and T4 . This may primary (Graves disease) or rarely, secondary (due to pituitary or hypothalamic diseases).

- The diagnosis is based on clinical features and laboratory data. 

Lab Test

- The measurement of serum TSH concentration provides the most useful single screening test for hyperthyroidism, because TSH levels are decreased in primary cases, even when the disease is still be subclinical. 
- In secondary cases TSH levels are either normal or raised. 
- A low TSH value is usually associated with increased levels of free T4 . 
- Occasionally, hyperthyroidism results from increased levels of T3 .

DYSPLASIA
 It is disturbed growth or  cells in regard to their size, shape arrangement. In its mild degrees it represents a reversible reaction to chronic inflammation whereas the most severe degrees warrant a labelling of intraepithelial neoplasia. Hence it includes a wide spectrum of changes ranging from a reversible disorientation to 'carcinoma-in-situ'.

Histologically it is characterized by:

o    Basal cell hyperplasia.
o    Variation in size and shape of cells.
o    Disorderly maturation.
o    Increased mitotic activity.
o    Disorientation of arrangement of cells (loss of polarity)

Dysplasia is commonly seen in:

o    Squamous epithelium of cervix.
o    Bronchial epithelium in habitual smokers.
o    Gastric and colonic mucosa in long standing inflammation
o    Oral and vulval leucoplakia