There is nothing a parent can do before, during or after a pregnancy to cause osteopetrosis in a child.The genes associated with osteopetrosis are involved in the development and/or function of osteoclasts, cells that break down bone tissue when old bone is being replaced by new bone (bone remodeling). This process is necessary to keep bones strong and healthy. Mutations in these genes can lead to abnormal osteoclasts, or having too few osteoclasts. If this happens, old bone cannot be broken down as new bone is formed, so bones become too dense and prone to breaking. Mutations in the CLCN7 gene cause most cases of autosomal dominant osteopetrosis, 10-15% of cases of autosomal recessive osteopetrosis (the most severe form), and all known cases of intermediate autosomal osteopetrosis. Mutations in the TCIRG1 gene cause about 50% of cases of autosomal recessive osteopetrosis. Mutations in the IKBKG gene cause X-linked osteopetrosis. Mutations in other genes are less common causes of osteopetrosis. In about 30% percent of affected people, the cause is unknown.Normally, bone growth is a balance between osteoblasts (cells that create bone tissue) and osteoclasts (cells that destroy bone tissue). Those with osteopetrosis have a deficiency of osteoclasts, meaning too little bone is being resorbed, resulting in too much bone being created. Gene variation
Mechanisms
Normal bone growth is achieved by a balance between bone formation by osteoblasts and bone resorption (breakdown of bone matrix) by osteoclasts. In osteopetrosis, the number of osteoclasts may be reduced, normal, or increased.
Naftifine hydrochloride (brand names include Exoderil and Naftin) is an allylamine antifungal drug for the topical treatment of tinea pedis, tinea cruris, and tinea corporis (topical fungal infections). Naftifine has triple action: antifungal, antibacterial, and anti-inflammatory. Its fungistatic activity is believed to be based on inhibition of the squalene-2,3-epoxidase enzyme, which in turn results in the shortage of ergosterol required for the formation of fungal cell membranes. With some fungal species, there is also fungicidal activity from a resulting accumulation of squalenes, leading to damage of the fungal cell membranes, including at the endoplasmatic reticulum. The half-life is approximately 2–3 days. The metabolites are excreted in the urine and feces.Naftifine was invented at the Sandoz Research Institute in Vienna, Austria. It was the first succesful antifungal medication of the allylamine class. Naftifine shows mostly fungicidal activity toward dematophytes and molds, and mostly fungistatic activity toward yeasts. It is also effective as an antibacterial agent in treating pyoderma. Naftifine is almost completely metabolized in the human body, with a half-life of 2–3 days. Its metabolytes do not have antifungal activity, and they are excreted with urine and bile. == References ==