UV-B damages eyes of barnacle larvae and impairs their photoresponses and settlement success.

The impact of enhanced UV-B radiation on marine ecosystems due to ozone depletion has caused growing global concern. Barnacle larvae have evolved complex photoreceptors and elaborate phototactic behaviors, which enable them to identify suitable habitats for feeding and settlement. For the first time, we demonstrate that environmentally realistic levels of UV-B radiation can induce ocular damage in barnacle larvae, thereby impairing the phototactic behavior of naupliar larvae and reducing settlement success of cypris larvae. Significant disruptions of rhabdomeres (the photosensitive structures in which phototransduction takes place) occurred in the retinular cells of naupliar eyes when naupliar larvae were exposed to a UV-B dose of 7.2 kJ m(-2), and impairment was dependent upon dose rather than irradiance. Our experimental data also showed that phototaxis of nauplii was ca. 4 times more sensitive to UV-B than settlement of cyprids. Since barnacles play an important role in the function and structure of coastal systems worldwide, any impairment of phototactic and settlement behavior of the larvae would pose a significant threat to the sustainability of this ecologically important species. The fact that enhanced UV-B radiation can induce ocular damage and subsequent phototactic impairment in barnacle larvae suggests that UV-B may also cause similar damage to other zooplankton species.

Alternations in quantities and activities of erythrocyte cytosolic carbonic anhydrase isoenzymes in glucose-6-phosphate dehydrogenase-deficient individuals.

BACKGROUND: This study was designed to evaluate the quantitative and activity alterations of cytosolic carbonic anhydrase (CA) isoenzymes in the erythrocytes of glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals. METHODS: Western Blot and CA esterase activity analysis were employed to measure cytosolic erythrocyte CA isoenzymes. RESULTS: The total CA activities were analyzed from erythrocytes of 30 healthy and 30 G6PD-deficient individuals. The mean values with standard error (SE) were 22.9+/-1.69 U/gHb and 27.2+/-2.1 U/gHb (P<0.01), respectively. The ratio of CAI/CAII of G6PD-deficient individuals (1.28+/-0.06) was significantly lower than that of the normal subjects (3.79+/-0.18) (P<0.001). Furthermore, the concentration of CAIII in G6PD-deficient individuals was significantly lower than that of the normal subjects (P<0.001) and there were significant correlations between the concentration of CAI, CAII, CAIII, and ratio of CAI/CAII, and the activity concentration of G6PD. CONCLUSIONS: Different carbonic anhydrase isoenzymes may serve different roles in the G6PD-deficient erythrocyte. CAI could be used as an indicator for hemolytic anemia. CAII is able to compensate for the functions of CAI and increased expression of CAII will promote oxidative damage. CAIII can provide the G6PD-deficient persons with some extent of protection against oxidative damage.

Total body bone mineral content in small-for-gestational -age, appropriate-for-gestational -age, large-for-gestational -age term infants and appropriate-for-gestational -age preterm infants.

BACKGROUND: Metabolic bone disease is a recognized complication in very low birth weight infants. Inadequate postnatal intake of calcium and phosphorus is probably important in the pathogenesis of bone disease in the newborn. A few studies have shown lower bone mineral content at birth in small for gestational age (SGA) than in appropriate for gestational age (AGA) infants. The present study was designed to compare total body bone mineral (TBBM) content in AGA, SGA, and large for gestational age (LGA) term infants. Also, it was designed to evaluate extrauterine changes in TBBM in preterm infants. METHODS: Ten SGA [mean +/- S.D. birth weight (B.W.) was 1.7 +/- 0.2 Kg, gestational age (G.A.), 39.0 +/- 0.8 weeks], ten AGA (B.W.; 3.3 +/- 0.4 Kg; G.A.: 39.3 +/- 1.4 weeks), ten LGA (B.W.: 4.4 +/- 0.3 Kg; G.A.: 40.4 +/- 0.9 weeks) term infants and ten AGA preterm infants (B.W.: 1.6 +/- 0.3 Kg; G.A.: 31.9 +/- 1.9 weeks) were enrolled in this study. TBBM content was measured using dual-photon-absorptiometry at 1 week postnatally in SGA, AGA, LGA term infants and in preterm infants at 1, 6, 12 weeks postnatally. Serum total calcium, phosphorus, magnesium, alkaline phosphatase activity (alk-p), parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OHD) and urinary calcium, phosphorus, creatinine were measured at 1 week postnatally in all studied infants and 6, 12 weeks, postnatally in preterm infants. Preterm and SGA term infants received premature formula enriched with calcium, phosphorus and vitamin D. RESULTS: There was no significant difference (p > 0.05) in serum calcium, phosphorus, magnesium, alk-p, PTH, 25-OHD and urinary calcium, phosphorus, creatinine values among SGA, AGA and LGA term infants at one week of age. Also, there was no significant difference in serum biochemical values in preterm infants at 1, 6, 12 weeks postnatally. Significantly lower (p < 0.05) urinary phosphorus values were found in preterm than in term infants. TBBM content was lower (p < 0.05) in SGA term infants than in AGA and LGA term infants. Premature infants had lower (p < 0.01) TBBM values than term AGA infants; however, TBBM values increase with postnatal age in preterm infants. CONCLUSIONS: Biochemical or marked radiological evidence of metabolic bone disease did not develop in any of the studied preterm infants. It appears that feeding permature infants with formula enriched with phosphorus, calcium and vitamin D may provide sufficient mineral for bone mineralization.

[Postoperative hypoglycemia after pheochromocytoma resection].

A case of severe hypoglycemia (30 mg/dL) after resection of unilateral pheochromocytoma is reported. Consciousness regained after 20 gm dextrose water was given intravenously. Rebound insulin storm is highly suspected as the main mechanism for the development of post-operative hypoglycemia. Administration of alpha and beta adrenergic blockers may also contribute to the severity of the hypoglycemia. Closely monitoring blood sugar level during the perioperative period is the only way to prevent the occurrence of such a catastrophe.

Biochemical evaluation of riboflavin and vitamin B6 status of institutionalized and non-institutionalized elderly in Central Kentucky.

A study was conducted to assess the nutritional status of riboflavin and vitamin B6 of the elderly in Central Kentucky. Elderly subjects aged 60 to 95, including 42 men and 77 women, were randomly selected: 41 from six nursing homes and 78 from private residences. Blood and urine samples were collected for analysis. Riboflavin and vitamin B6 status were assessed by using glutathione reductase activation coefficient and glutamic-pyruvic transaminase activation coefficient, respectively. Glutathione reductase activation coefficients ranged from 0.88 to 1.89 with a mean +/- SD of 1.23 +/- 0.22, and were not significantly correlated with the urinary excretion of riboflavin. Glutamic-pyruvic transaminase activation coefficients ranged from 0.86 to 1.50 with a mean +/- SD of 1.16 +/- 0.14, and were negatively correlated with urinary excretion of 4-pyridoxic acid. Riboflavin deficiency was found in 34.2 percent of the institutionalized and 27.7 percent of the non-institutionalized subjects, while vitamin B6 deficiency was found in 56.6 percent of the institutionalized and 43.5 percent of the non-institutionalized subjects studied. The institutionalized elderly showed significantly poorer riboflavin status (P less than 0.01) and vitamin B6 status (P less than 0.05) than the non-institutionalized elderly. Aging was associated with a significant decline in both riboflavin (P less than 0.01) and vitamin B6 status (P less than 0.05).