Parathyroid hormone (PTH) function as immunologic mediator has become interesting with the recent usage of PTH analogue (teriparatide) in the management of osteoporosis. Since the early 1980s, PTH receptors were found on most immunologic cells (neutrophils, B and T cells).
But, the refrigerator will only keep food safely cold for about four hours if unopened during a power outage, according to the USDA. A full freezer will hold the temperature for about 48 hours if full (24 hours of half full), the USDA says. Generally, if the temperature in the thermometer in the freezer reads 40 degrees Fahrenheit or below, the food is safe and can be refrozen, according to the USDA.
Do not open the refrigerator or freezer door unless absolutely necessary in order to maintain the cold temperature. A full freezer will keep food frozen for about 48 hours. A freezer that is half full will keep food frozen for about 24 hours. An unopened refrigerator will keep food cold for about 4 hours. If available, add ice to the refrigerator to keep the food at a safe temperature if the power will be out for long periods of time. Do not place frozen food outside, even in winter.