Pericardial or pleural effusion

Causes
The cause that directly leads to BAL is unclear. Exposure to radiation, chemical exposure, virus and genetics are the primary reasons proposed by researchers. Mechanisms
The mechanism of BAL is related to several mutations. The most common abnormalities are t(9;22) and MLL gene rearrangement at 11q23. T(9;22) affect the ABL gene at 9q34 and BCR at 22q11. The hybrid gene product ABL/BCR is an oncogene which could lead several types of leukemia including BAL. ABL/BCR could active several molecular pathways:

RAS signaling could be activated by BCR/ABL by GRB2 adaptor which interact with Y177 of BCR. Through AKT/PKB, PI3-K pathway could also be activated. STAT5, 1, and 6 has been reported that is a major molecular signaling event activated by BCR/ABL. Some focal adhesion complex (PAXILLIN, FAK0 could be activated by BCR/ABL with adaptor molecule CRK-L.
BCR/ABL could inactivate negative regulatory molecules PTP1B and Abi-1. Their inactivation is related with progression into blast crisis. BCR/ABL pathway could also active PI64K/Akt/STAT5 pathway which has anti-apoptotic activity. BCR/ABL induce cell adhesive and migratory abnormalities because the mutation will lead an abnormal response to chemokine SDF-1
MLL gene encode Histone-lysine N-methyltransferase (HRX), which is a histone methyltransferase. It is a positive regulator for gene transcription. It has been shown that associates with Host cell factor C1, CREB binding protein, WDR5, CTBP, MEN1, etc. The rearrangement of MLL are related with different kinds of aggressive acute leukemias. Most of biphenotypic leukemia in children is due to the rearrangement of MLL

Besides them, other gene abnormalities has been reported.
The use of a louse comb is the most effective way to detect living lice.The most characteristic symptom of infestation is pruritus (itching) on the head which normally intensifies 3 to 4 weeks after the initial infestation. The bite reaction is very mild and it can be rarely seen between the hairs. Excessive scratching of the infested areas can cause sores, which may become infected. Treatment
The number of diagnosed cases of human louse infestations (or pediculosis) has increased worldwide since the mid-1960s, reaching hundreds of millions annually. There is no product or method which assures 100% destruction of the eggs and hatched lice after a single treatment. However, there are a number of treatment methods that can be employed with varying degrees of success. These methods include chemical treatments, natural products, combs, shaving, hot air, silicone-based lotions, and ethanol (ethyl alcohol).Pediculosis is commonly treated with permethrin lotion. Epidemiology
About 14 million people, mainly children, are treated annually for head lice in the United States alone. Only a small proportion of those treated, however, may have objective evidence of an extant infestation. High levels of louse infestations have also been reported from all over the world including Denmark, Sweden, U.K., France and Australia. Normally head lice infest a new host only by close contact between individuals, making social contacts among children and parent child interactions more likely routes of infestation than shared combs, brushes, towels, clothing, beds or closets.