Restoration of vision after transplantation of photoreceptors.

Cell transplantation is a potential strategy for treating blindness caused by the loss of photoreceptors. Although transplanted rod-precursor cells are able to migrate into the adult retina and differentiate to acquire the specialized morphological features of mature photoreceptor cells, the fundamental question remains whether transplantation of photoreceptor cells can actually improve vision. Here we provide evidence of functional rod-mediated vision after photoreceptor transplantation in adult Gnat1−/− mice, which lack rod function and are a model of congenital stationary night blindness. We show that transplanted rod precursors form classic triad synaptic connections with second-order bipolar and horizontal cells in the recipient retina. The newly integrated photoreceptor cells are light-responsive with dim-flash kinetics similar to adult wild-type photoreceptors. By using intrinsic imaging under scotopic conditions we demonstrate that visual signals generated by transplanted rods are projected to higher visual areas, including V1. Moreover, these cells are capable of driving optokinetic head tracking and visually guided behaviour in the Gnat1−/− mouse under scotopic conditions. Together, these results demonstrate the feasibility of photoreceptor transplantation as a therapeutic strategy for restoring vision after retinal degeneration.

Serum biochemical markers of bone turnover in healthy infants and children.

Serum osteocalcin (OC), bone alkaline phosphatase (BAP), carboxyterminal propeptide of type I procollagen (PICP), carboxyterminal telopeptide of type I collagen (ICTP), parathyroid hormone (PTH) and 1,25 dihydroxyvitamin D [1,25(OH)2D] were measured in 241 normal infants and children (134 males and 107 females aged 1.9 months-14 years, 1.8 months-12 years, respectively). Regarding the analysis of data for children above 2 yrs, we chose data with the following normalization: data/body surface x standard body surface, to eliminate biological variations not exclusively related to chronological age. The increase in serum OC occurred at the expected age of growth spurts in both sexes: in the first year of life OC values (mean +/- SD) were 82.6 +/- 34.3 and 60.2 +/- 32.9 OC ng/ml in males and females, respectively; during puberty, peak values occurred at the age of 10-12 yrs in girls (76.6 +/- 25.8) and at the age of 12-14 yrs in boys (113 +/- 48.3). Furthermore, significant positive correlations with age were found for males from 2 to 14 yrs (p < 0.00001) and for females from 2 to 12 yrs (p < 0.001). Elevated levels of BAP occurred in the first year, 70.4 +/- 28.2 and 71.8 +/- 28.5, and in the second year, 69.4 +/- 26.7 and 67.4 +/- 33.8 ng/ml, for males and females, respectively. For children older than 2 yrs, a positive correlation with age (p < 0.01) was found for females only, with a peak value of 67.2 +/- 13.9 at the age of 10-12 yrs. For ages 2-14 yrs the reference values (mean +/- 2SD) were 15.5 - 90.3 and 17.2 - 95.2 ng/ml for males and females, respectively. The highest PICP levels (1354 +/- 680 ng/ml in males and 1041 +/- 766 in females) were observed in infants less than 1 year of age, decreasing by about 60% at the age of 2. There was no significant change in serum PICP for children older than 2 yrs with values covering a range (mean +/- 2SD) of 52 - 544 and 18 - 546 ng/ml in males and females, respectively. Similarly, the highest ICTP values were seen in infants younger than 1 year (29.7 +/- 11.7 and 29.5 +/- 20.1 ng/ml in males and females, respectively). In the ages from 2 to 14 yrs there did not seem to be any systematic age-correlated changes, with values covering a range (mean +/- 2SD) of 6.06 - 24.5 in boys and 6.84 - 22.9 ng/ml in girls. Serum PTH concentrations (mean +/- SD) in infancy were 27.2 +/- 19.3 pg/ml for males and 25.8 +/- 10.8 for females. Normal ranges (mean +/- 2SD) in the older group were 5.77 - 53.1 and 6.71 - 57.3 pg/ml for males and females, respectively. Serum 1,25(OH)2D presented values of 47.3 +/- 28.1 and 38.7 +/- 18.2 pg/ml under 2 yrs for males and females, respectively. The ranges (mean +/- 2SD) in children above 2 yrs were 9.5 - 101 pg/ml in boys and 10.9 - 88.4 in girls. The results of this study contribute to the establishment of reference values in normal children for these biochemical assays; these reference values are needed when the above biological markers will be applied in the monitoring of metabolic bone diseases.

Lipoprotein abnormalities in chronic renal failure and dialysis patients.

Lipoprotein abnormalities are common in patients with chronic renal failure (CRF) on either dialysis or conservative therapy. In order to investigate the changes in lipid and apolipoprotein pattern from early CRF to dialysis treatment, plasma lipids with apoproteins AI, B, E, CII, CIII, CII/CIII ratio, E/CIII ratio, parathyroid hormone (PTH) and insulin levels were examined in 72 patients with different degrees of CRF and 31 patients on hemodialysis (HD), and compared the values of 28 controls. A significant decrease in the Apo CII/CIII ratio was the earliest lipoprotein abnormality to occur in CRF. Hypertriglyceridemia (HTG) with reduced high-density lipoprotein cholesterol levels, increased Apo CIII and decreased Apo E/Apo CIII ratio only occurred in more advanced renal failure (creatinine clearance < 31 ml/min). HD patients showed a general worsening of the lipoprotein profile with elevated Apo E levels and indirect evidence of remnant accumulation. While PTH did not have any significant influence on lipoprotein pattern, increased insulin levels during HD might partly account for the HTG of these patients. Our results point to elevated Apo CIII, reduced Apo CII/Apo CIII and Apo E/ Apo CIII ratios as typical features of uremic hyperlipidemia and show that a defective triglyceride removal is the major pathogenetic mechanism of uremic HTG. HD treatment seems generally to worsen the lipid and apolipoprotein pattern observed in the predialytic stage of CRF.

Intraoperative fall in plasma levels of intact parathyroid hormone in patients undergoing parathyroid adenomectomy.

Intraoperative measurement of intact parathyroid hormone (PTH) can be used to evaluate the success of parathyroid surgery in primary hyperparathyroidism associated with parathyroid adenoma. To evaluate this approach we used a modified immunoradiometric assay (IRMA) to study the kinetic patterns of circulating PTH disappearance in 13 patients undergoing adenomectomy for single adenoma. The rapid and the standard assay for PTH measurement in plasma were used and compared. The two methods showed a highly significant correlation (r = 0.995; p < 0.0001). We reported a decrease in PTH to 18.2 +/- 2.30 (mean +/- SEM) from baseline values at 15 minutes after successful parathyroid adenomectomy in the 13 patients. The biphasic pattern of serum PTH clearance was calculated in 8 of the studied patients with a fast phase showing a half-life (T1/2) of 3.99 (SEM 0.464) minutes and a slow phase with a T1/2 of 91.0 (SEM 33.6) minutes. Half the amount of the basal values was reached between 4 and 9 minutes. Our study concludes that the modified IRMA for intraoperative measurement is feasible, reliable and sufficiently precise for low hormone values. Since it may yield information on the half-life of PTH in the circulation, it may play a role in the surgical guidance for total exeresis of hyperfunctioning tissue.

Serum amylase and tissue polypeptide antigen as biochemical indicators of salivary gland injury during iodine-131 therapy.

The study evaluated the possibility of using serum alpha-amylase and tissue polypeptide antigen (TPA) as biochemical markers of radiation injury in the salivary gland of patients with thyroid carcinoma treated with iodine-131. The results demonstrated that the two molecules increased 1 day after 131I administration and returned to near control values on the 3rd day. The increase was greater and longer lasting in those patients treated with the higher 131I administered activity. However, when the patients were divided into groups based on recovery time, which determined patients with different radionuclide elimination rates, the increase in the two molecules was greater and more lasting in those subjects with a longer period of hospitalization. A comparison with the values obtained from patients with tumours of the head and neck treated with external radiotherapy demonstrated that after the 1st day of treatment the salivary gland received an absorbed dose which, based on alpha-amylase levels, ranged between 0.24 and 1.89 Gy and, based on TPA levels, between 0.28 and 2.29 Gy.

Serum 25-hydroxyvitamin D levels in normal subjects: seasonal variations and relationships with parathyroid hormone and osteocalcin.

The measurement of human 25-hydroxyvitamin D (25-OH-D) serum levels has a potential role in evaluating calcium and bone metabolism disorders. To determine normal ranges were studied, cross-sectionally, a healthy population of men and women, aged 18-69 years, over a 12-month period. Changes in 25-OH-D levels for the examined population fitted a mathematical model that demonstrated a highly significant periodic relationship to time. Gender had a significant (p < 0.03) effect on mean 25-OH-D concentration, but age was not significantly correlated with 25-OH-D in either sex. A 95% tolerance band was computed in order to have a time-qualified "range of normality" with circannual periodicity. Interesting periodic variations were seen for the parathyroid hormone (PTH) as well as for osteocalcin (OST). A moderate negative correlation was found between 25-OH-D and PTH in both sexes, with more significant evidence in males. No relationship was observed between 25-OH-D and OST.

Lipids and apolipoproteins change during the progression of chronic renal failure.

Uremic hyperlipidemia was recently suggested to contribute to progression of chronic renal failure (CRF). To investigate the relationship between lipoprotein abnormalities and decline of renal function, plasma lipids with apoproteins A1, B, E, CII, CIII, CII/CIII and E/CIII ratios, parathyroid hormone (PTH), insulin and glucose levels were examined in 72 patients with different degrees of CRF and compared to 28 patients of a reference group. A significant decrease of CII/CIII ratio was already evident below a Ccr of 60 ml/min, while increased apo-CIII and triglycerides (TG) with reduced HDL-cholesterol (HDL-C) levels occurred below a Ccr of 30 ml/min. Both TG and apo-CIII showed a positive correlation with creatinine levels. On the contrary, apo-CII/apo-CIII and HDL-C inversely correlated with the progression of renal failure. PTH and insulin showed a positive correlation with TG, the former being also inversely related to apo-CII/apo-CIII ratio. Our results point to early apolipoprotein changes in the course of CRF. Elevated apo-CIII and reduced apo-CII/apo-CIII ratio may be considered the most typical features of uremic hyperlipidemia and likely account for the impaired TG removal and the hypertriglyceridemia (HTG). Secondary hyperparathyroidism may contribute to reduce peripheral lipolytic activity and cause HTG. A contributory role of hyperlipidemia in the progression of renal disease is also supported.

Cell kinetics and biochemical parameters in breast cancer.

The study analyzes biochemical and cell kinetic parameters to characterize solid tumor growth in humans. The concentrations of polyamines, CEA, the thymidine labeling index (T.L.I.) and the mitotic index (M.I.) were determined on fragments of neoplastic tissue from 18 patients with breast carcinoma. Urinary polyamines were evaluated in the same patients. Two groups of patients were distinguished according to the median value of the with high T.L.I., M.I. and tissue polyamines were significantly higher than in the group with low T.L.I., whereas tissue CEA was lower, though in a not statistically significant way. Urinary polyamines showed no variations between groups. These preliminary results showed that T.L.I. levels were higher in patients who relapsed during a 4-year follow-up than in patients achieving complete remission and remaining disease free. Results concerning polyamine concentration showed that the tissue polyamine level in breast carcinoma indicated proliferative activity, but this does not seem to be valuable for current prognostic purposes.

Serum NSE, CEA, CT, CA 15-3 levels in human lung cancer.

The significance of neuron specific enolase (NSE) was investigated in comparison with other tumor markers (CEA, CT, CA 15-3) used in the diagnosis and treatment monitoring of lung cancer. As previously described, the calcitonin assay proved to have very low sensitivity for small cell lung cancer (SCLC). The serum NSE assay was, however, shown to be a useful diagnostic aid for discrimination between histologically different lung cancers, and therefore this assay may be a valuable tool for treatment monitoring in SCLC patients. CA 15-3, also an unspecific marker, showed similar sensitivity to the NSE assay in SCLC patients, the sensitivity being higher than CEA in non small cell lung cancer (NSCLC).

Enzyme activities in ageing small intestine and modifications after irradiation.

Brush border enzyme activities in control rats of different ages were studied. Disaccharases, dipeptidases and alkaline phosphatase levels were similar in both age groups. When the rats were sacrificed at two different times of the day the activity was significantly lower in the morning than in the evening in both adult and young animals. No similar differences were observed in lysosomal activities. After irradiation the enzyme activities in both groups presented the same patterns although variations were more marked in adult animals. At 120 hrs the tendency to return to control levels appeared less evident in adult rats. Morphologic data confirmed these results.

Dipeptidase activity in the small intestine after irradiation at different times of the day.

The behaviour of leucinaminopeptidase, an intestinal epithelium brush border enzyme, was investigated to find out whether the same irradiation does administered at different times of the day would induce differentiated modifications. Three activity phases were evidenced: increase, reduction during acute damage, and recovery. The results showed that the general behaviour in the four irradiated groups was similar, although some differences were observed mostly regarding the outset of the initial increase and the recovery. The time of irradiation affects the behaviour of the enzyme activities which show circadian oscillations. The results seem to show a quicker tendency to a return to normal values in the group irradiated at the end of the darkness period.

14C leucine uptake in rat tissues at different times after irradiation.

The uptake of 14C leucine administered at different intervals after irradiation, but always 4 and 8 h before the animals were killed, has been evaluated in tissues with different proliferative activity and protein synthesis. The results have demonstrated an increased uptake and a more rapid elimination of the tracer after irradiation. In the small intestine a lower amount of TCA insoluble fraction was observed when the morphologic injury was evident, while protein synthesis significantly increased during the initial phase of appearance of the injury and mainly during the recovery phase of epithelial cells. Kidney and plasma had levels higher than controls at all intervals.

Post-irradiation enzyme activities of the rat small intestine: effects on circadian fluctuations.

The effects of ionizing radiations on circadian fluctuations in the activities of small bowel mucosal enzymes were studied. The fluctuations in activities of brush-border enzymes disappeared after irradiation coincidentally with changes in their activity. This change was particularly pronounced with leucinaminopeptidase. At longer periods after irradiation (50 and 74 hours) when the whole epithelium showed morphological changes, the activity of brush-border enzymes was very low. The activity of lysosomal enzymes (which do not show circadian fluctuations) increased when the epithelium showed marked morphological modifications and the stroma contained numerous inflammatory cells.