Supplementation of nanofiltrated deep ocean water ameliorate the progression of osteoporosis in ovariectomized rat via regulating osteoblast differentiation

Magnesium was reported to be necessary for bone formation. Previous study indicated nanofiltrated deep ocean water (DOW) rich in magnesium. This study investigated the potential mechanisms of DOW in ameliorating osteoporosis. Briefly, female Sprague-Dawley rat was ovariectomized and fed with 0.35, 0.7, or 1.4 ml/kg of DOW daily for 8 weeks. In the results, DOW increased bone density, decreased trabecular bone loss, and decreased bone adiposity. DOW improved bone mass by examining structure in micro-computed tomography. About 0.35 and 0.7 ml/kg of DOW can increase protein expression of runt-related transcription factor 2 (RUNX2), an essential transcription factor for regulating osteoblast differentiation, by 9.4% or 12.9%. In human osteoblast, DOW increased the levels of osteocalcin, RUNX2, and alkaline phosphatase; all the proteins can regulate osteoblast differentiation. Considering the results of in vivo and in vitro study, DOW can ameliorate ovareictomy-caused osteoporosis via regulating the osteoblast differentiation, thereby, maintenance of bone structure. PRACTICAL APPLICATIONS: In addition to calcium, magnesium is essential to promoting the deposition of calcium in bones and regulating its transport; it may also slow the progression of osteoporosis. Nanofiltrated DOW contains abundant magnesium along with several microelements and peptides. In this study, a product was developed for decelerating osteoporosis by using an estrogen depletion model. DOW regulates osteoblast differentiation and thus prevents osteoporosis. This finding provides an alternative healthy source of bone supplements. In addition to tablets or capsules, aqueous supplements can be produced to achieve osteoporosis prevention. This finding is beneficial to the health-care industry for developing sustainable supplements.

3D localization of clustered microcalcifications using cranio-caudal and medio-lateral oblique views

This paper presents a 3D localization method to register clustered microcalcifications on mammograms from cranio-caudal (CC) and medio-lateral oblique (MLO) views. The method consists of three major components: registration of clustered microcalcifications in CC and MLO views, 3D localization of clustered microcalcifications and 3D visualization of clustered microcalcifications. The registration is performed based on three features, gradient, energy and local entropy codes that are independent of spatial locations of microcalcifications in two different views and are prioritized by discriminability in a binary decision tree. The 3D localization is determined by a sequence of coordinate corrections of calcified pixels using the breast nipple as a controlling point. Finally, the 3D visualization implements a virtual reality modeling language viewer (VRMLV) to view the exact location of the lesion as a guide for needle biopsy. In order to validate our proposed 3D localization system, a set of breast lesions, which appear both in mammograms and in MR Images is used for experiments where the depth of clustered microcalcifications can be verified by the MR images.

Body composition changes following laparoscopic gastric banding for morbid obesity

Most reports of outcome following obesity surgery report weight and co-morbidity changes only. We studied body composition changes in 17 adult patients (15 F, 2 M, age 43+/-2 years, range 28-58 years), with morbid obesity (initial BMI 40.4+/-4.9 kg/m(2), range 34.7-48.8) who were managed surgically by laparoscopically inserting an adjustable gastric band. Body composition was studied before and after surgery (mean interval of 909+/-51 days, range 441-1155 days) using anthropometry (abdominal circumference, AC, sum of four skinfold thicknesses, SFSUM), whole-body potassium counting (TBK), in vivo neutron activation analysis total body nitrogen (TBProtein) and whole-body dual-energy ray absorptiometry (total body percent fat TBF%, and total body bone mineral density TBBMD). Weight loss over the study period was 23.4+/-2.5 kg. ( p<0.0003) with an AC reduction of 20.0+/-4.5 cm ( p<0.008). Both SFSUM and TBF% were significantly reduced ( p<0.02 and p<0.0005 respectively). Both TBK and TBProtein after normalization for sex and height, were significantly ( p<0.0054 and p<0.001 respectively) reduced, but the ratio of loss of fat mass to fat-free mass, at 4.4:1 was usual for weight loss, and there was no significant changes in the ratio of potassium to protein. TBBMD, after normalization relative to a young same sex adult, was not significantly changed. In this group of patients, most of the substantial weight loss over a 2- to 3-year period was due to loss of fat mass, with relatively less reduction in the components of fat-free mass. Adjustable laparoscopic gastric banding induces fat loss without significant other deleterious effects on body composition.

Orthogonal subspace projection-based approaches to classification of MR image sequences

Orthogonal subspace projection (OSP) approach has shown success in hyperspectral image classification. Recently, the feasibility of applying OSP to multispectral image classification was also demonstrated via SPOT (Satellite Pour 1'Observation de la Terra) and Landsat (Land Satellite) images. Since an MR (magnetic resonance) image sequence is also acquired by multiple spectral channels (bands), this paper presents a new application of OSP in MR image classification. The idea is to model an MR image pixel in the sequence as a linear mixture of substances (such as white matter, gray matter, cerebral spinal fluid) of interest from which each of these substances can be classified by a specific subspace projection operator followed by a desired matched filter. The experimental results show that OSP provides a promising alternative to existing MR image classification techniques.

PDGF-BB and IGF-I use different signaling pathways to induce fibronectin synthesis in cultured rat thoracic aortic smooth muscle cells

Fibronectin, an extracellular matrix protein, acts as an early signal in initiating cell proliferation. Results have indicated that platelet-derived growth factor BB (PDGF-BB) and insulin-like growth factor-I (IGF-I) both enhance fibronectin gene expression. Genistein inhibits PDGF-BB-induced fibronectin levels without inhibiting IGF-I-induced fibronectin levels. It indicates that PDGF-BB and IGF-I utilize separate signaling pathways to induce the synthesis of fibronectin.

PDGF-BB and IGF-I use different signaling pathways to induce NaK-ATPase subunits in cultured rat thoracic aortic smooth muscle cells

(Na(+)+K(+))-adenosine triphosphatase (NaK-ATPase), an ubiquitous membrane transport protein consisting of alpha and beta subunits, regulates Na(+)/K(+)fluxes and maintains many vital physiological functions, including cell growth. Results have indicated that platelet-derived growth factor (PDGF) and insulin-like growth factor-I (IGF-I) both enhance NaK-ATPase subunits. Genistein, an inhibitor of tyrosine phosphorylation, inhibits serum- and PDGF-BB-induced NaK-ATPase alpha(1)subunit protein levels without inhibiting IGF-I-induced NaK-ATPase alpha(1)subunit protein levels. These results indicate that PDGF-BB and IGF-I utilize separate signaling pathways to induce the synthesis of NaK-ATPase alpha(1)subunits. In addition, genistein failed to inhibit PDGF-BB-stimulated NaK-ATPase beta(1)subunit levels, suggesting that two separate pathways are involved to induce the synthesis of the NaK-ATPase alpha(1)and beta(1)subunits, respectively.

Determination of retinoic acid and retinol at physiological concentration by HPLC in Caucasians and Japanese women

A sensitive, specific and simple method for simultaneous determination of retinoic acid and retinol in human serum by reverse phase HPLC with UV detector has been developed. Retinoic acid is measurable at physiological concentration in human serum by this method. There is no significant difference in serum retinoic acid level between Caucasian and Japanese subjects. However, the serum retinol level in Japanese women is significantly lower than that in Caucasian women.

Identification and characterization of a protease from Streptococcus oralis C104

Streptococcus oralis is among the earliest colonizers of the tooth surface during plaque formation. As such, its enzymatic activities may influence ecologic succession on the tooth surface. In the current study, we use zymograms and preparative polyacrylamide gel electrophoresis to identify and purify a protease from S. oralis (sanguis) C104. Proteases from S. oralis C104 were detected in cell pellets at 133, 146 and 176 kDa as clear proteolytic bands on gelatin-substrate zymograms. Preparation of the major (146 kDa) protease were obtained by continuous-elution electrophoresis. The protease was active over the pH range of 7 to 9 with optimum activity between pH 8 and 9. Protease activity was inhibited by several serine protease inhibitors including phenylmethylsulfonyl fluoride, di-isopropyl-phosphofluoridate and aprotinin. The protease showed highest hydrolytic activity against azoalbumin and Bz-Pro-Phe-Arg-NA. Immunofluorescence studies with a polyclonal antiserum to the 146-kDa protease suggest it is present on the cell surface of S. oralis C104. Zymograms of cell pellets from other S. oralis strains as well as S. sanguis and Streptococcus mitis suggest that functionally similar proteases are elaborated by many early colonizers of the tooth surface.

In vitro shear strength of bonded amalgam cores with and without pins

This study compared the shear bond strength of resin-bonded amalgam with and without pins. The coronal third of 240 embedded posterior teeth was removed to expose a flat, nonretentive surface. Three Minikin pins were placed in the dentin in a triangular pattern 1 mm apart. Amalgam was condensed into a Delrin mold (4.2 mm in diameter and 3 mm in height) positioned over each tooth. The adhesives Amalgam-bond, All-bond, Amalgambond with high-performance additive, Panavia EX, and Panavia with Photobond were the materials used to bond the amalgam to the dentin. Half of the samples were immersed in normal saline solution for 7 days and the others for 30 days. Shear bond strengths were recorded as the maximum load per cross-sectional area of the bonded surface with a testing machine with 1 kN load cell and crosshead speed of 0.5 mm/min. A three-factor analysis of variance and Student-Newman-Keuls test (p = 0.05) identified Amalgambond with high-performance additive as the strongest adhesive in this study. The use of pins with or without adhesives increased the shear strength of amalgam samples significantly more than samples that used adhesives alone.

Regulation of fibronectin by insulin-like growth factor-I in cultured rat thoracic aortic smooth muscle cells and glomerular mesangial cells

We examined the regulation of fibronectin (FN) levels by insulin-like growth factor-I (IGF-I) in rat thoracic aortic smooth muscle cell (SMC) and glomerular mesangial cell cultures. IGF-I enhances FN levels in the culture media of the SMC and in the cell samples of the mesangial cells. It shows no effect on FN levels in the cell samples of the SMC and in the culture media of the mesangial cells. Modulation of IGF-I-induced FN levels by insulin was also examined. Insulin enhances FN levels in the culture media of the SMC but not in the cell samples. Insulin did not induce an increase in FN levels in either the mesangial cell samples or the culture media. No additive effect of FN levels was observed when the SMC were treated with insulin and IGF-I together. The effect of IGF-I on FN mRNA levels was assessed. IGF-I enhances SMC and FN mRNA levels, implying that acquisition of additional FN mRNA units accounts for the increase in FN levels. The effects of actinomycin D and cycloheximide on IGF-I-induced FN mRNA levels were also examined. Inhibition of the IGF-I-induced FN mRNA levels by actinomycin D and an increase of FN mRNA levels by cycloheximide suggest that IGF-I regulates FN mRNA synthesis at the transcriptional level.

Preferred meal patterns in non-insulin-dependent diabetes

Current advice on the across-the-day distribution of energy and carbohydrate intakes in non-insulin-dependent diabetes (NIDD) is based on inadequate evidence. We have addressed this by a comparison of an even as opposed to a main evening meal pattern in 11 subjects with NIDD. Contributions of macronutrients to energy intake were fat 29%, protein 20% and carbohydrate 51% with each meal pattern. The peak glycaemic response in the morning was not as good as the response in the evening (P<0.01), where an even energy and carbohydrate spread was used; this contrasts with previous reports in healthy subjects where the morning response to glucose is better than that later in the day. This difference between peak morning and peak evening glycaemic response was not seen with a main evening meal. There was a lower overall glycaemic response with a main evening meal compared with an even meal pattern (P<0.01, by area comparison). The overall insulin response was not significantly different between the two meal patterns, although the sensitivity for insulin appeared better in the evening where there was an evening main meal.

Determination of tocotrienol and tocopherol isomers at physiological concentration by HPLC in Caucasian and Japanese women

A sensitive, specific and simple method for simultaneous evaluation of tocopherol and tocotrienol isomers in human serum by normal phase HPLC with a fluorescence detector has been developed. Tocopherol and tocotrienol isomers are measurable in physiological concentration in human serum by this method. There is no significant difference in serum alpha- and beta-tocopherols and alpha-, gamma-, and delta-tocotrienols between Caucasian and Japanese subjects. However, serum gamma- and delta-tocopherol concentrations in Japanese women are significantly higher than in Caucasian women.

Regulation of rat renal (Na(+) + K+)-adenosine triphosphatase mRNA levels by corticosterone

We investigated the mechanisms for glucocorticoid regulation of rat renal NaK-ATPase activity. Our findings suggest that the magnitudes of corticosterone-induced increases in alpha 1 mRNA and beta 1 mRNA levels are similar in the kidney of the adult adrenalectomized rats. The results also suggest that corticosterone restores NaK-ATPase activity in adrenalectomized rats prior to any enhanced sodium delivery.

Neomycin inhibits mastoparan-induced lactate dehydrogenase release, ethidium bromide accumulation, and intracellular fluorescein depletion in MDCK cells

Mechanisms of cell death induced by toxins probably involve one or more processes such as inhibition of protein synthesis and impairment of plasma membrane integrity leading to an increase in membrane permeability. Since one of the possible actions of mastoparan, a cationic tetradecapeptide from wasp venom, is to perturb membrane phospholipids resulting in an increase in membrane permeability, we studied the effect of chemically synthesized mastoparan on lactate dehydrogenase release (LDH), ethidium bromide and fluorescein accumulation in Madin-Darby Canine Kidney (MDCK) cultured cells. Our results demonstrated that mastoparan induced cytosolic LDH release, ethidium bromide accumulation and intracellular fluorescein depletion in MDCK cells. Neomycin, a polycationic aminoglycoside, interacts with anionic polyphosphoinositides at the plasma membrane. Since both mastoparan and neomycin are cationic peptides and react with the negatively charged membrane phospholipids, we studied the interaction of these two peptides on membrane permeability. Our results demonstrated that neomycin inhibited mastoparan-induced LDH release, ethidium bromide accumulation and intracellular fluorescein depletion.

Mastoparan increases membrane bound phosphatidylinositol kinase and phosphatidylinositol 4-monophosphate kinase activities in Madin-Darby canine kidney cells

Synthetic wasp venom Mastoparan induced an increase of [3H] inositol phosphates levels and a corresponding decrease of [3H]inositol phospholipids levels in Madin-Darby canine kidney (MDCK) cells. The effect was dose (5-100 micrograms/ml) and time (1 to 15 min) dependent. Mastoparan also enhanced the endogenous activity of phosphatidylinositol kinase and phosphatidylinositol 4-monophosphate kinase. The effect was dose (25-75 micrograms/ml) and time dependent (1 to 15 min).

Mastoparan inhibits rat renal NaK-ATPase activity

Rat renal NaK-ATPase was inhibited by mastoparan in a dose dependent fashion. This inhibition reached completion within 30 seconds. Due to mastoparan's rapid effects on NaK-ATPase activity, this inhibition does not appear to involve either a decrease in the rate of synthesis or an increase in their degradation of NaK-ATPase since these processes require a latency period of at least several minutes. In addition, the phosphoenzyme intermediate formed in the presence of mastoparan was greater than that formed in its absence further indicating that inhibition of NaK-ATPase by mastoparan is not due to a decrease in the number of NaK-ATPase. A possible mechanism for the inhibition is that mastoparan stabilizes the phosphoenzyme intermediate and reduces the Vmax of the enzyme by decreasing the rate of turnover of existing enzyme sites. Neomycin, an inhibitor of inositol phospholipid metabolism, was also found to attenuate the inhibition of Na,K-ATPase by mastoparan, suggesting that the mechanism of this inhibition may involve degradation of the phosphatidylinositol "pool".

Inhibition of alpha-aminoisobutyric acid uptake by mastoparan in Madin-Darby Canine Kidney cells

Mastoparan, a wasp venom, was found to inhibit Na(+)-dependent net alpha-aminoisobutyric acid (AIB) uptake in Madin Darby Canine Kidney (MDCK) cells. Mastoparan also produced a significant increase in AIB efflux when compared to controls. Pretreatment of MDCK cells with 2 mM neomycin attenuated mastoparan's inhibition of net AIB uptake and completely suppressed mastoparan-mediated increases in AIB efflux when compared to controls. These data suggest that mastoparan's inhibition of net AIB uptake involves more than a single basic mechanism.

Food variety is associated with less macrovascular disease in those with type II diabetes and their healthy controls

In developed countries, the health outcome most under scrutiny with respect to food intake is macrovascular disease. Since food is so complex, global indices of food intake are required to assess the relation. In the present study, an index of food variety was examined for its ability to predict changes in the arterial wall. Arterial wall indices were measured noninvasively by Doppler ultrasound in patient with Type II diabetes and in matched apparently healthy subjects. Each subject kept a 7-day food record, which was cross-checked by a nutritionist so as to calculate an index of food variety. The arterial wall indices measured were compliance over the aorto-iliac segment and pulse wave damping at the common femoral and posterior tibial arteries. Significant correlations, both parametric and nonparametric, were found between total food variety, and plant food variety, and each arterial wall index when the diabetics and apparently healthy subjects were grouped together (p less than 0.01 in all cases for total variety and at least less than 0.05 for plant food variety). Between 13 and 19% of the variance in arterial wall indices was explained by food variety.

Fish intake and arterial wall characteristics in healthy people and diabetic patients

The relation between fish consumption and indices of arterial wall pathology was investigated in 31 healthy subjects and in 22 patients with non-insulin-dependent diabetes mellitus (NIDDM). Arterial compliance in non-fish eaters, as measured by doppler ultrasonography, was significantly lower than that in fish eaters in the healthy group, in the NIDDM group, and in the two groups combined. In non-fish eaters an increase in proximal resistance at the common femoral artery and in the posterior tibial artery was significant only in the combined groups and in healthy subjects, respectively. The results support the hypothesis that fish consumption may be important for better arterial wall characteristics.

Evaluation of dietary fibre in meals-on-wheels meals in Melbourne

The elderly are considered to be a group of persons who are at risk of suffering the health problems that are associated with inadequate nutrition. The delivery of meals to homes, the meals-on-wheels programme, has been an approach to reduce this risk, but there is little information about the contribution of such a programme to the total diet or to particular nutrient intakes. The dietary-fibre content of meals that were collected over four seasons from three Melbourne metropolitan meals-on-wheels areas was determined chemically and compared with the fibre content as calculated by means of food-composition tables. The analysed and calculated dietary-fibre contents of meals-on-wheels meals were 7.3 g and 6.4 g, respectively. The total daily dietary-fibre intake was assessed in recipients of the meals-on-wheels services by a three-day food-record, and also by means of a dietary history. The dietary-fibre intake was 16 g/day by both methods. Most dietary fibre came from vegetables; the fruit fibre was derived exclusively from citrus fruit, and no cereal fibre was provided, except in desserts. The contribution of meals-on-wheels meals to the estimated daily dietary-fibre intake of meals-on-wheels recipients was 46% as determined by chemical analysis and 40% as calculated from food-composition tables. The contribution of meals-on-wheels meals to a suggested desirable total intake of dietary fibre of 25-30 g/day for the elderly was 24%-29% as analysed and 21%-26% as calculated. Thus, the contribution of meals-on-wheels meals to the total dietary-fibre intake was reasonable but low in comparison with the desirable intake. Home-delivered meals could contain higher levels of dietary fibre by the inclusion of more foods which contain whole-grain cereals, nuts, legumes and vegetables.

Effects of triiodothyronine on resting membrane potential of primary cultured rat submandibular gland cells

The effect of triiodothyronine (T3) on the resting membrane potential was measured in primary cultured rat submandibular gland cells. The resting membrane potential was 29.5 +/- 0.71 mV. The hormone T3, at concentrations of 10(-9) M or greater, hyperpolarized the cells 5.8 mV (p less than 0.05). Hyperpolarization was complete within 24 hours. Ouabain (1 mM) depolarized the cells 5.9 mV. Cells exposed to T3 and ouabain had the same membrane potential as cells treated with ouabain alone. These data suggest that the hyperpolarization observed can be, in part, attributed to triiodothyronine-induced synthesis of (Na-K)-adenosine triphosphatase.

Putative determinants of arterial wall compliance in NIDDM

Aortoiliac arterial wall compliance was measured in apparently healthy subjects and in patients with non-insulin-dependent diabetes (NIDDM), on diet alone, who had no clinical evidence of peripheral arterial disease. Compliance was significantly lower in patients with diabetes. The two clinical groups were combined to provide as wide a range of blood glucose values as possible. After allowing for the influence of age, there were significant negative correlations between compliance and free fatty acid and insulin levels. These were almost completely accounted for by differences in blood glucose levels. Therefore, arterial compliance was best predicted on the basis of age and the area under the blood glucose curve.

Cardiotoxin from cobra venom increases the level of phosphatidylinositol 4-monophosphate and phosphatidylinositol kinase activity in two cell lines

In rat basophilic leukemia-2H3 (RBL-2H3) and Madin-Darby canine kidney (MDCK) cells, cardiotoxin from cobra venom induced a marked decrease in the level of [3H] phosphatidylinositol and a corresponding increase in the level of [3H]phosphatidylinositol 4-monophosphate over the course of 20 min as demonstrated in cells that had been labeled to equilibrium with [3H]inositol. The effect was dependent on the concentration (5-30 micrograms/ml) of the toxin. In plasma membrane-enriched fractions isolated from the two cell lines, the cardiotoxin enhanced the endogenous activity of phosphatidylinositol kinase especially at temperatures above 14 degrees C. In RBL-2H3 cells, cardiotoxin also induced release of substantial amounts of histamine and lactate dehydrogenase. The release of histamine, but not of lactate dehydrogenase, was totally dependent on external calcium and this release probably represented an exocytotic response of the cells to cardiotoxin. Although, initially, treatment with the toxin did not impair antigen-induced hydrolysis of inositol phospholipids or prevent the antigen-induced rise in the concentration of cytosol Ca2+, prolonged exposure to the toxin did result in a progressive loss of responsiveness of RBL-2H3 cells to antigen.

Effect of triiodothyronine on system A amino acid transport in cells of rat submandibular gland

The effect of L-3,5,3'-triiodothyronine (T3) on alpha-aminoisobutyric acid (AIB) transport in isolated cell suspensions of rat submandibular gland was investigated. The uptake of ATB by these cells appeared to require extracellular Na+ and was inhibited by ouabain (10(-3) M). Cell suspensions from thyroidectomized rats which have been given three successive doses of T3 on alternate days (50 micrograms/100 g BW) showed a significant increase in AIB uptake compared with cells isolated from thyroidectomized rats treated with diluent. Efflux of AIB from the cell suspension was not affected by T3. There was no significant changes in AIB uptake 12 h after a single injection of T3 (50 micrograms/100 g BW). However, there was a significant 49% and 65% increase in AIB net uptake at 24 and 48 h, respectively, after T3 treatment. Under similar conditions, the cell suspension showed a 48% increase in NaK-ATPase activity at 12 h and to a peak of 61% at 24 h. Therefore, changes in NaK-ATPase activity preceded the changes in AIB net uptake upon treatment with T3, implying that AIB uptake is probably mediated, at least in part, by the activity of NaK-ATPase.

Doppler ultrasound recognition of preclinical changes in arterial wall in diabetic subjects: compliance and pulse-wave damping

Doppler ultrasound was used to detect early changes in arteries of the legs by two independent techniques. Pulse-wave velocity was measured to calculate arterial wall compliance and Fourier analysis was used to measure damping of the pulse-wave forms. Ten non-insulin-dependent diabetic men with no clinical evidence of peripheral arterial disease had significantly lower compliance and greater pulse-wave damping than 10 matched nondiabetic control subjects. There was a good correlation between the results for the two different techniques.

Risk factors for changes in aorto-iliac arterial compliance in healthy men

Doppler ultrasound was used to measure pulse wave velocity down the aorta and iliac arteries. Arterial wall compliance was calculated from pulse wave velocity in 45 apparently healthy men. Their arterial compliance fell significantly with advancing age, raised blood pressure, increased serum cholesterol and triglyceride levels, and reduced serum high density lipoprotein cholesterol levels. The correlation between compliance and age was independent of the other risk factors, and the correlation between compliance and lipid status was independent of age and blood pressure. There was no significant correlation between compliance and area under the glucose tolerance curve.

Riboflavin status of adolescent southern Chinese: riboflavin saturation studies

Riboflavin saturation studies were done on 36 high-school boys in Canton whose mean daily intake of riboflavin was 0.45 mg and who showed clinical evidence of deficiency. The boys were given a 2 mg load of riboflavin orally followed by supplements of 0.5, 1.0 and 1.5 mg riboflavin to three groups; a control group received no supplement. After 14 days' supplementation, excretion of riboflavin had increased significantly in all supplemented groups, but not in the control group. The 4-h excretion of riboflavin after the 2 mg load averaged 8.6 per cent of the load for all groups before supplementation. After 14 days' supplementation it was significantly increased only in the groups receiving 1.0 and 1.5 mg daily. This suggests that tissue saturation may not be achieved until the background intake of 0.45 mg/d is increased by between a further 0.5-1.0 mg daily. After 17 days' supplementation with 1.0 and 1.5 mg riboflavin, scrotal dermatitis disappeared. However, even in the 0.5 mg supplemented group, eight out of ten boys with scrotal dermatitis had responded and a total intake of 0.95 mg/d may be enough to prevent clinical deficiency.

Riboflavin status of adolescents in southern China. Average intake of riboflavin and clinical findings

The average riboflavin intake of 11 200 schoolchildren, aged 12-19 years, in Guangdong Province, China, was measured. Food intake was measured by weighing, and riboflavin intake was calculated by means of food tables. The average intake of riboflavin was 0.45 mg/day. In addition, clinical observations were made in 1313 adolescents in the dietary survey. The findings were consistent with the low intake of riboflavin. The observed clinical signs of riboflavin deficiency were scrotal dermatitis (7.9% of boys), angular stomatitis (5.8% of boys, 2.7% of girls), cheilosis (8.0% of boys, 5.6% of girls) and magenta tongue (36.0% of boys, 40.8% of girls). Corneal vascularization was found only in two of the 1313 children. Scrotal lesions resolved within three to six days after the oral administration of riboflavin (15 mg/day); the resolution of tongue and lip signs progressed more slowly.

Corticosterone and triiodothyronine control of myocardial Na+-K+-ATPase activity in rats

Experiments were carried out to examine the effects of corticosterone and triiodothyronine on rat myocardial Na+-K+-ATPase activity. Corticosterone increased Na+-K+-ATPase activity when administered intravenously in multiple doses, a single dose, and different dosages. The possibility that enhancement of myocardial Na+-K+-ATPase activity by corticosterone is mediated by early changes in intracellular Na+ and K+ was investigated. Following a single dose of corticosterone (1 mg/100 g body wt), the increase in Na+-K+-ATPase activity preceded the changes in intracellular Na+ and K+. Corticosterone did not change the transition temperature and activation energy of the reaction in myocardial Na+-K+-ATPase. This implies that corticosterone does not act by altering the lipid matrix in the microenvironment of the Na+-K+-ATPase system. The interaction between the effects of corticosterone and triiodothyronine on myocardial Na+-K+-ATPase activity was examined. Our studies indicated that corticosterone and triiodothyronine regulate Na+-K+-ATPase activity via parallel independent pathways.

Regulation of rat renal (Na+ + K+)-adenosine triphosphatase activity by triiodothyronine and corticosterone

The present study concerns the effects of corticosterone and T3 on renal cortical and outer medullary NaK-ATPase activities in the rat. The results show that corticosterone increases cortical and outer medullary NaK-ATPase activities when administered as either a single or multiple doses. Corticosterone and T3 are known to enhance NaK-ATPase activity. We investigate the possibility of interaction between the effects of corticosterone and T3 on renal NaK-ATPase activity. Our studies indicate that corticosterone and T3 regulate renal cortical NaK-ATPase activity via parallel independent pathways, and that corticosterone appears to regulate medullary NaK-ATPase activity without participation by thyroid hormone.

Effect of thyroid hormone on carbohydrate content of Na+-K+-adenosine triphosphatase

The effect of L-3,5,3'-triiodothyronine (T3) (50 micrograms/100 body wt) on the incorporation of labeled glucosamine and fucose into the subunits of Na+-K+-ATPase was examined by gel electrophoresis in sodium dodecyl sulfate. T3 augmented the incorporation of glucosamine into the alpha- and beta-subunits by 51 and 58%, respectively, in the 22-h chase experiments. Similarly T3 augmented the incorporation of fucose into the alpha- and beta-subunits by 58 and 43%, respectively. Reverse T3 did not alter the incorporation of labeled fucose in either subunit. The effect of T3 on the rate constant of degradation of renal cortical Na+-K+-ATPase was assessed. The rate constant of degradation (Kd) of the [3H]fucose labeled alpha- and beta-subunits for the hypothyroid rats were both 0.20, and for T3-treated rats, the Kd of the alpha- and beta-subunits were 0.23 and 0.18, respectively, suggesting that T3 enhanced fucose incorporation into the subunits of Na+-K+-ATPase rather than retarding the degradation of this enzyme.

Diabetes and macrovascular disease: risk factors for atherogenesis and non-invasive investigation of arterial disease

This paper reviews the risk factors that may contribute to atherosclerotic vascular disease in diabetics. Many of the risk factors have been identified on the basis of cross-sectional clinical studies or from mortality data, and as a result various aetiological hypotheses about the mechanism of atherogenesis have been formed. Because of the importance of identifying changes in the arterial wall well in advance of the clinical events that lead to morbidity or mortality, emphasis is given also to the various techniques of non-invasive assessment of vascular disease that can be applied to diabetic as well as non-diabetic patients. One particular form of non-invasive investigation of arterial function, namely the Doppler pulse rate velocity and wave-form analysis, is comparatively simple. We present some preliminary data to suggest that this technique may be useful in the evaluation of pre-symptomatic stages of atherosclerosis in diabetes.

Effect of corticosterone and triiodothyronine on (Na+ + K+)-adenosine triphosphatase activity in rat submandibular gland

The present study concerns the effect of glucocorticoids and triiodothyronine (T3) on rat salivary (Na+ + K+)-adenosine triphosphatase (NaK-ATPase). The results indicate that corticosterone increases submandibular gland NaK-ATPase activity with a single dose of hormone and with two daily doses on three successive days. Multiple injections of dexamethasone also increases submandibular and sublingual gland NaK-ATPase activity. The effect of glucocorticoids on salivary NaK-ATPase is selective since Mg-ATPase shows no significant differences under different steroidal states. We subsequently investigate the possibility of interaction between the effects of corticosterone and triiodothyronine on submandibular gland NaK-ATPase activity. Our studies indicate that each of these hormones increases NaK-ATPase activity in the absence of the other.

Effect of triiodothyronine on (Na+ G K+)-adenosine triphosphatase and (Na+ + Mg2+)-dependent phosphorylated intermediate in rat salivary glands

The present studies concern the effect of triiodothyronine (T3) on rat salivary (Na+ + K+)-adenosine triphosphatase (NaK-ATPase). The results indicate that T3 selectively increased submandibular and parotid NaK-ATPase units with a single, large dose of T3, different dosage of T3, three successive doses of T3 given on alternate days, and "physiological" doses of T3 with daily injection for 2 weeks. Sublingual NaK-ATPase was insensitive to T3 in the above experiments. The effect of T3 on submandibular and parotid NaK-ATPase is selective since Mg-ATPase and 5'-nucleotidase showed no significant differences under different thyroid status. The lack of response of NaK-ATPase to reverse T3, further substantiates the specificity of T3 on salivary NaK-ATPase.

Triiodothyronine augments the number of membrane-bound (Na+-K+)-adenosine triphosphatase units, but does not affect the sedimentation properties of plasma membrane components

We have previously demonstrated that T3 enhanced the de novo synthesis of renal cortical (Na+-K+)-dependent ATPase (NaK-ATPase) in the rat. A purified membrane fraction obtained from successive centrifugation of renal cortical crude homogenate was used in the above studies. To rule out a possible effect of T3 on plasma membrane properties, such as the sedimentation characteristic of NaK-ATPase, we have presently observed T3-dependent increases in the activity and number of NaK-ATPase units in a crude homogenate of rat renal cortex. The following results were obtained which substantiate a specific effect of T3 on the membrane-bound NaK-ATPase system. 1) Compared to the hypothyroid state, 43% and 44% increases in the activity and number of NaK-ATPase units, respectively, were observed in crude renal cortical homogenate of T3-treated hypothyroid rats. 2) In comparison with the crude homogenate prepared from hypothyroid rats, 4.8- and 113-fold increases in the specific activity of NaK-ATPase were obtained in the L and J fractions, respectively. Increases of similar relative magnitude in the L and J fractions were also shown in T3-treated hypothyroid and euthyroid rats. 3) No difference in the recovery of the number of NaK-ATPase units was observed from successive steps of the purification under different thyroid states. 4) Treatment of renal cortices from hypothyroid, T3-treated hypothyroid, and euthyroid rats with deoxycholate increased to the same extent NaK-ATPase activity and phosphorylated intermediate formation.

Effect of triiodothyronine on renal growth and renal sodium reabsorption in hypothyroid rats

Experiments were carried out to compare temporal changes in the paraaminohippuric acid clearance (CPAH), renal sodium reabsorption (RNa+), ribonucleic acid (RNA), and deoxyribonucleic acid (DNA) content in hypothyroid rats after a single injection of triiodothyronine (T3) (50 micrograms/100 g body wt). CPAH and RNa+ showed no changes at 24 and 48 h. At 72 h, however, significant increases of 41% and 42% (per g kidney wet wt) were observed in CPAH and RNa+, respectively. The cortex in T3-treated hypothyroid rats showed a significant increase in the protein/DNA and RNA/DNA ratios at 24 h and progressive increases to a level of 24%, and 37%, respectively, at 48 h. No changes in DNA content were observed at either time-points. The results show that the increases in RNA/DNA and protein/DNA ratios upon T3 treatment preceded the increases in CPAH and RNa+, suggesting a direct effect of T3 on renal cortical growth, rather than a secondary response to a primary increase in renal functions.

Relationship between Na+-dependent respiration and Na+ + K+-adenosine triphosphatase activity in the action of thyroid hormone on rat jejunal mucosa

Administration of three successive doses of triiodothyronine (T3) (50 micrograms/100 g body wt), given on alternate days to thyroidectomized and euthyroid rats, stimulated oxygen consumption (QO2) and Na+ transport-dependent respiration (QO2 [5]) in the stripped jejunal mucosa, a preparation that consisted mostly of epithelial cells. The increase in QO2(t) accounted for 57% of the increment in QO2 in the transition from the hypothyroid to the euthyroid state and for 29% of the increment in the transition from the euthyroid to the hyperthyroid state. Administration of T3 to hypothyroid rats also increased the yield of epithelial cells. Injection of T3 into thyroidectomized and euthyroid rats increased the specific activity (at Vmax) of the (Na+ + K+)-dependent adenosine triphosphatase (NaK-ATPase) in jejunal crude membrane preparations. No significant change was recorded in the activity of Mg-ATPase in the same preparation. The ratio of QO2/NaK-ATPase and QO2(t)/NaK-ATPase in the various thyroid states remained constant, indicating proportionate increased in the respiratory and enzymatic indices. The effect of administration of T3 to thyroidectomized rats on the number of NaK-ATPase units (recovered in the crude membrane preparation) was estimated by: (a) Na+ + Mg++ + ATP-dependent binding of [3H]-ouabain to crude membrane fractions, and (b) the amount of the phosphorylated intermediate formed in the NaK-ATPase reaction from AT32P(gamma). Estimates were obtained of the maximal number of [3H]ouabain binding sites (Nm) and dissociation constants (Kd). Nm for [3H]ouabain and Nak-ATPase specific activity increased to about the same extent after T3 administration to thyroidectomized rats, with no change in the apparent Kd values. The amount of phosphorylated intermediate formed in jejunal crude membrane preparations also increased significantly. Thus, thyroid hormone administration may increase the number of active Na+pump sites in the plasma membrane. The apparent increase in the number of Na+ pump sites also correlated with the hormone dependent increases in QO2 and QO2(t).

Thyroxine and Na+ transport in toad: role in transition from poikilo- to homeothermy

The effects of thyroxine (T4) on Na+ transport, oxygen consumption (QO2), and Na+-K+-ATPase activity were studied in the urinary bladder and liver of the toad Bufo marinus. In the bladder, T4 in vitro (10(-8) to 10(-6) M) had no significant effect on these parameters during 15 h of incubation. When injected intraperitoneally (approximately 20 microgram/(kg body wt.day) for 6 days), T4 lowered base-line, short-circuit current by 62% (P less than 0.0025) and potential difference by 37% (P less than 0.001), increasing tissue resistance by 40% (P less than 0.02). T4 depressed QO2/DNA (-25%, P less than 0.05) with no significant effect on Na+-K+-ATPase activity. In liver, T4 increased the recovery per cell DNA of mitochondrial proteins by 32% (P less than 0.025), corresponding to an increased QO2 (stage IV) of isolated mitochondria per cell DNA (+54%, P less than 0.01). There was no significant effect on Na+-K+-ATPase activity. These results suggest that, unlike its function in the rat, T4 in the toad does not regulate cellular thermogenesis by inducing Na+-K+-ATPase. This major difference could account at least in part for the transition from poikilothermy to homeothermy. In addition, T4 has a distinct inhibitory effect on Na+ transport in the urinary bladder, which suggests an antagonism to the action of aldosterone.

Time course of the renal response to triiodothyronine in the rat

Experiments were carried out to compare temporal changes in glomerular filtration rate (GFR), filtered Na+ load, and renal cortical (Na+ + K+)-adenosine triphosphatase (Na-K-ATPase) activity in the hypothyroid rat after administration of a single dose of triiodothyronine (T3) (50 microgram/100 g body wt). The cortex showed an increase in Na-K-ATPase at 24 h and progressive increases to a peak of 62% at 48 h. GFR and filtered Na+ load showed no changes at 24 and 48 h. At 72h, however, significant increases of 62 and 63% (per rat) were observed in GFR and filtered Na+ load, respectively. The results show that the early increase in Na-K-ATPase activity upon T3 treatment precedes the increases in GFR and filtered Na+ load, suggesting a direct effect of T3 on the regulation of Na-K-ATPase activity in the hypothyroid rat kidney cortex, rather than a secondary response to a primary increase in filtered Na+ load as proposed previously.

Effect of triiodothyronine on the synthesis and degradation of renal cortical (Na+ + k+)-adenosine triphosphatase

The present studies concern the roles of synthesis and degradation of the large subunit of (Na+ + k+)-adenosine triphosphatase (NaK-ATPase) in the response to triiodothyronin (T3). Single doses of either the diluent of T3 (50 mug/100 g body weight) were given to two pairs of surgically thyroidectomized rats. Twenty hours after injection, the rats received 3H- or 35S-labeled methionine administered as a constant injusion into the tail vein for 1 h. The kidneys were removed either 8 h or 20 h after infusion and the eight kidneys were divided into pairs, as follows. I, 3H (diluent)/35S (T3); II, 35S (diluent)/3H (T3); III, 3H (diluent)/35S (diluent); IV, 3H (T3)/35S (T3). Partially purified NaK-ATPase was prepared from the pooled homogenates and prepared from the pooled homogenates and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAG-electrophoresis). The large subunit of NaK-ATPase was identified by (Na+ + mg2+)-dependent and K+-sensitive incorpotation of 32P from [gamma-32P]ATP. This component had an estimated molecular weight of 92,000 and migrated as a single peptide in gels of varying total carylamide concentration, with respect to: (1) Coomassie blue staining, (b) (Na+ + Mg2+)-dependent, K+-sensitive incorporation of 32P from [gamma-32-P]ATP, and (c) T3-dependent enhanced incorporation of labeled methionine. T3 augmented incorporation of labeled methionine into the large subunit by 44% 8 h after infusion of the amino acid and by 61% 20 h after infusion. Incorporation of methionine into two adjacent polypeptides in the SDS gels was unaffected by thyroid status. The effect otical NaK-ATPase was assessed by a double label technique. Pairs of thyroidectomized rats were injected with either the diluent or 50 mug of T3/100 g body weight at 48-h after the first injection (diluent or T3, i.e. Day "zero"). Kidney cortices were processed on either Day 4 or Day 6; the partially purified NaK-ATPase fraction was prepared, labeled with [gamma-32P]ATP, and analyzed by SDS-PAG-electrophoresis. The degredation rate constants of the large subunit were similar; 0.145 and 0.124 day-1 for the hypothyroid and T3-treated groups, respectively. Thus, the T2-dependent increase in incorporation of labeled methionine into the large subunit appears to result from enhanced synthesis and this increase is sufficient to account for the entire increase in both the number of the activity of the NaK-ATPase units.

Sugar transport by intestine. Escape of galactose from preloaded mucosa of hamster jejunum

Everted hamster jejunum was loaded with D-galactose and then escape into an initially galactose-free mucosal solution was followed. Mucosal anaerobiosis greatly increased the rate of escape, an effect which might have been caused by inhibiting reuptake from the unstirred layer and/or by augmenting the ease of unidirectional efflux across the brush border membrane. The former effect was expected because of our previous results from influx studies, and the main object here was to find out if the ease of efflux is affected by anaerobiosis. With phlorizin present in the mucosal solution during escape, information about unidirectional efflux was obtainable. We estimated that 10(-4) M phlorizin inhibited the ease of efflux via the phlorizin-sensitive pathway by about 65%. Apparently the reason why mucosal phlorizin accelerates escape of sugar from loaded mucosa, an effect which has been reported previously by others, is that it inhibits unidirectional efflux less effectively than it inhibits reuptake from the unstirred layer. Residual efflux via the phlorizin-sensitive pathway was markedly increased by mucosal anaerobiosis. This increase did not require an elevation of intracellular Na+ concentration. These results, together with those of our previous study, show that mucosal anaerobiosis abolishes uphill transport of galactose across the brush border of hamster jejunum by inhibiting unidirectional influx and by increasing the ease of unidirectional efflux. Neither of these effects requires a rise in intracellular Na+ concentration.