ABSTRACT
Purpose: microgravity causes major changes in various systems of the body in space, such as shift in cerebrospinal fluid, decreased red blood cells count, and electrolyte loss. These complications are very important in space and we should find new approaches to prevent the side effects of microgravity in astronauts
Materials and Methods: this experimental study was conducted on 21 adult male rats in three groups: control, Hind-limb unloaded, Hind-limb unloaded plus Erythropoietin. SPSS software was used for data analysis. RBC indices were assessed in the first, third and fourteenth day in different groups
Results: the highest mean of hemoglobin was 17.98 +/- .35 in the Hind-limb unloaded plus Erythropoietin group [on the 3[rd] day] and the lowest amount was 13.52 +/- 1.22 in the Hind-limb unloaded group [on the 14[th] day]. The P value to compare RBC and reticulocyte count in Hindlimb unloaded group with those in Hind-limb unloaded plus Erythropoietin group was .017 [on the3[rd] day], to compare hemoglobin in Hind-limb unloaded group with that in Hind-limb unloaded plus Erythropoietin group was 0.004 [on the 3[rd] day], and to compare reticulocyte values in Hind-limb unloaded group with those of Hind-limb unloaded plus Erythropoietin group was 0.036 [on the 14[th] day]
Conclusion: the lowest amount of RBC indices was in the Hind-limb unloaded group [on the 14[th] day]. RBC indices were significantly higher in Hind-limb unloaded plus Erythropoietin group than those on the 1[st] day. Erythropoietin injection induced significant improvement in RBC indices in rats under microgravity condition. Erythropoietin is very useful to prevent space anemia and its highest effect occurson the 3[rd] day after injection. This is as an innovative method to prevent space anemia
ABSTRACT
Hypertension is the most prevalent risk factor for arterial disease in the industrialized world and is a frequently encountered clinical problem in the aircrew population. Arterial systolic and diastolic blood pressures are continuously varying quantities, influenced by a host of extraneous factors. Aviators with hypertension responsive to life-style modifications should have serial BP rechecks quarterly to semi-annually during the first year to assure success of the lifestyle modifications. Failure to achieve blood pressure control with lifestyle modifications, or an initial blood pressure average exceeding 160 mmHg systolic or 100 mmHg diastolic, requires initiation of pharmacotherapy. In this study we evaluate books, magazines, articles, guidelines and reliable websites related to aeromedical concerns and waiver considerations in aircrew with hypertension. Two major "types" of essential hypertension are generally recognized. One is characterized by suppressed renin activity and sensitivity to dietary sodium, the other by high renin activity and a lack of response to sodium intake. Thiazide diuretics are certainly the initial therapy of choice, particularly for older subjects. Aircrew with blood pressure that is controlled adequately with thiazides, with no other uncontrolled cardiovascular risk factors, and with no evidence of end-organ damage, are usually fit to return to unrestricted flying in military and civilian spheres. ACE inhibitors are an alternative initial choice in younger aviators, are positively indicated in patients with type 2 diabetes, and have no adverse effects on serum lipids. Hydrochlorothiazide [hctz], with or without triamterene or potassium replacement, can be used as a first line agent for treatment of hypertension in designated personnel. ACE inhibitors might have an adverse effect on G-tolerance have not been borne out by experience in either the US Air Force or the Royal Air Force [RAF], and the US Navy accepts these agents for unrestricted flying without G-tolerance testing