Cyclopia: from Greek antiquity to medical genetics.

Cyclops are among the best-known monsters of Greek mythology, also mentioned in art and literature. According to the most recent scientific knowledge, the malformations caused by defective development of the anterior brain and midline mesodermal structures include cyclopia (synophthalmos), ethmocephaly, cebocephaly and arrhinencephaly. These severe forebrain lesions often are accompanied by severe systemic malformations, and affected infants rarely survive. Neither true cyclopia nor synophthalmos are compatible with life because an anomalous development of the brain is involved. Thus, it is difficult to assume that ancient Greeks drew their inspiration from an adult patient suffering from cyclopia. Cyclops appear for the first time in literature in Homer's Odyssey (8th-7th century BC) and one of them, Polyphemus, is blinded by the hero of the epic poem. The description of the creature is identical with patients suffering from cyclopia; eyes are fused and above the median eye there is a proboscis, which is the result of an abnormal development of the surface ectodermal structures covering the brain. The next literature appearance of Cyclops is at the end of 7th century BC in "Theogonia", written by Hesiodus. Another interesting description is made by Euripides in his satyr play entitled 'Cyclops' (5th century BC). In conclusion, though it is not certain whether Homer's description of Cyclops was based on his personal experience or the narration of his ancestors, there is no doubt that the ophthalmological disease, cyclopia, was named after this mythical creature.

Magnesium loss in magnesium deficient subjects with and without physical exercise during prolonged hypokinesia.

OBJECTIVE: To show the effect of hypokinesia (HK; diminished movement) on magnesium (Mg2+) loss in Mg2+ deficient subjects and the effect of physical exercise and on Mg2+ deficiency with and without physical exercise: Mg2+ balance, serum Mg2+ concentration and Mg2+ loss were measured. METHODS: Studies were conducted on 30 healthy male volunteers during a pre-experimental period of 30 days and an experimental period of 364 days. They were divided equally into three-groups: unrestricted active control subjects (UACS), continuous hypokinetic subjects (CHKS) and periodic hypokinetic subjects (PHKS). The UACS group ran average distances of 9.3 +/- 1.2 km.day-l; the CHKS group walked average distances of 0.9 +/- 0.2 km.day-l; and the PHKS group walked and ran average distances of 0.9 +/- 0.2 km and 9.3 +/- 1.2 km.day-l for 5-and 2-days per week, respectively. RESULTS: Mg2+ deficiency, serum Mg2+ level, fecal and urine Mg2+ loss increased (P < 0.05), in the PHKS and CHKS groups compared with their pre-experimental values and the values in the UACS group. However, serum Mg2+ concentration, urine and fecal Mg2+ loss and Mg2+ deficiency increased more (P < 0.05) in the PHKS group than in the CHKS group. CONCLUSIONS: Mg2+ deficiency is more evident with than without physical exercise and Mg2+ loss is exacerbated more with higher than lower Mg2+ deficiency. This indicates that Mg2+ deficiency with and without physical exercise and Mg2+ loss with higher and lower Mg2+ deficiency is due to inability of the body to use Mg2+ and more so when physically healthy subjects are submitted to prolonged periodic than continuous hypokinesia.

Potassium loss with tissue potassium deficiency in rats during hypokinesia.

BACKGROUND: This study aims at showing the effect of hypokinesia (HK) on tissue potassium (K(+)) loss with different tissue K(+) depletion and tissue K(+) deficiency with different K(+) intake. To this end, tissue K(+) content, plasma K(+) level, and K(+) loss with and without K(+) supplements during HK were measured. METHODS: Studies were conducted on male Wistar rats during a pre-experimental and an experimental period. Animals were equally divided into four groups: unsupplemented vivarium control rats (UVCR), unsupplemented hypokinetic rats (UHKR), supplemented vivarium control rats (SVCR), and supplemented hypokinetic rats (SHKR). SVCR and SHKR were supplemented daily with 2.50 mEq potassium chloride (KCl). RESULTS: Gastrocnemius muscle and right femur bone K(+) content reduced significantly, whereas plasma K(+) level and urine and fecal K(+) loss increased significantly in SHKR and UHKR compared with their pre-experimental values and the values in their respective vivarium controls (SVCR and UVCR). Bone and muscle K(+) content decreased more significantly, and plasma K(+) level and urine and fecal K(+) loss increased more significantly in SHKR than in UHKR. CONCLUSIONS: The greater tissue K(+) deficiency with higher than lower K(+) intake shows that the risk of higher tissue K(+) deficiency is directly related to K(+) intake. The higher K(+) loss with higher tissue K(+) deficiency and the lower K(+) loss with lower K(+) tissue deficiency shows that the risk of greater K(+) loss is directly related to tissue K(+) deficiency. Tissue K(+) deficiency increases more when the K(+) intake is higher and K(+) loss increases more with higher than lower tissue K(+) deficiency indicating that, during HK, tissue K(+) deficiency is due to the inability of the body to use K(+) but not to K(+) shortage in the diet.

Mechanism of sodium loss with muscle sodium deficiency in sodium supplemented and unsupplemented subjects during hypokinesia.

BACKGROUND: This study aims at showing the effect of hypokinesia (HK) on sodium (Na+) loss with different muscle Na+ deficiency and different Na+ intake. Muscle Na+ content, plasma Na+ level and Na+ loss with and without Na+ supplementation were measured. METHODS: This study was conducted on 40 healthy male volunteers during a pre-experimental and an experimental period. Subjects were equally divided into four groups: unsupplemented active control subjects (UACS), unsupplemented hypokinetic subjects (UHKS), supplemented active control subjects (SACS) and supplemented hypokinetic subjects (SHKS). A daily supplementation of 3.21 mmol of sodium chloride (NaCl) per kg body weight was given to subjects in the SACS and SHKS groups. RESULTS: Muscle Na+ content levels decreased and plasma Na+ levels, and levels of Na+ loss in urine and feces increased (p<0.05) in the SHKS and UHKS groups compared to their pre-experimental values and the values in the respective active control groups (SACS and UACS). However, muscle Na+ content levels decreased more (p<0.05), and plasma Na+ levels and levels of Na+ loss in urine and feces increased more (p<0.05) in the SHKS group than in the UHKS group. CONCLUSIONS: The greater muscle Na+ deficiency with higher than lower Na+ consumption shows that the risk of greater muscle Na+ deficiency is directly related to Na+ consumption. The higher Na+ loss with higher than lower muscle Na+ deficiency shows that the risk of greater muscle Na+ loss is directly related to muscle Na+ deficiency. It is concluded that muscle Na+ deficiency is more evident when Na+ consumption is higher and that muscle Na+ loss was more exacerbated with higher than lower muscle Na+ deficiency indicating that during prolonged HK the muscle Na+ deficiency is due to the inability of the body to use Na+, but not to Na+ shortage in diet.

Phosphate deposition during and after hypokinesia in phosphate supplemented and unsupplemented rats.

The objective of this study was to show that prolonged restriction of motor activity (hypokinesia) could reduce phosphate (P) deposition and contribute to P loss with tissue P depletion. To this end, measurements were made of tissue P content, P absorption, plasma P levels, urinary and fecal P excretion of rats during and after hypokinesia (HK) and daily phosphate supplementation. Studies were conducted on male Wistar rats during a pre-hypokinetic period, a hypokinetic period and a post-hypokinetic period. All rats were equally divided into four groups: unsupplemented vivarium control rats (UVCR), unsupplemented hypokinetic rats (UHKR), supplemented vivarium control rats (SVCR) and supplemented hypokinetic rats (SHKR). Bone and muscle P content, plasma intact parathyroid hormone (iPTH) levels, P absorption, plasma P levels and urinary and fecal P excretion did not change in SVCR and UVCR compared with their pre-HK values. During HK, plasma P levels, urinary and fecal P excretion increased significantly (p<0.05) while muscle and bone P content, P absorption and plasma iPTH levels decreased significantly (p<0.05) in SHKR and UHKR compared with their pre-HK values and the values in their respective vivarium controls (SVCR and UVCR). During the initial 9-days of post-HK, plasma, urinary and fecal P levels decreased significantly (p<0.05), and plasma iPTH levels, muscle and bone P levels remained significantly (p<0.05) depressed in hypokinetic rats compared with their pre-HK values and the values in their respective vivarium control rats. By the 15th day, these values approached the control values. During HK and post-HK, changes in P absorption, plasma iPTH levels, and P levels in muscle, bone, plasma, urine and feces were significantly (p<0.05) greater in SHKR than in UHKR. Decreased tissue P content with increased P loss in animals receiving and not receiving P supplementation demonstrates decreased P deposition during HK. Higher P excretion with lower tissue content in SHKR and UHKR demonstrates that P deposition is decreased more with P supplementation than without. Because SHKR with a lower tissue P content showed higher P excretion than UHKR it was concluded that the risk of decreased P deposition with greater tissue P depletion is inversely related to P intake, that is, the higher the P intake the greater the risk for decreased P deposition and the greater tissue P depletion. It was shown that P (regardless of the intensity of its tissue depletion) is lost during HK unless factors contributing to the decreased P deposition are partially or totally reversed. It was concluded that dissociation between (decreased) tissue P content and (increased) P uptake indicates decreased P (absorption and) deposition as the main mechanisms of tissue P depletion during prolonged HK.