Osteogenic responses of human mesenchymal stromal cells to static stretch

Molecular signals driving the regenerative process in distraction osteogenesis (DO) involve a complex system of cellular behavior triggered by mechanical strain. However, it remains unclear how mesenchymal stromal cells (MSCs) adapt to osteogenic demands during DO. We hypothesized that human MSCs (hMSCs) modulate early osteogenic metabolism during exposure to static stretch. The proliferation of hMSCs was increased by static stretch, which, in turn, suppressed TGF-β1-mediated decreases in cell proliferation. The amount of stretching force applied had little effect on osteoblast differentiation of hMSCs induced by dexamethasone treatment. However, this strain induced sustained production of nitric oxide and vascular endothelial growth factor (VEGF), which are critical factors in angiogenesis, from differentiated hMSCs. Mechanical stretch involved ERK and p38 mitogen-activated protein kinase pathways, the selective inhibitors of which decreased static-stretch-induced VEGF production. These findings provide evidence that hMSCs act to facilitate early osteogenic metabolism during exposure to static stretch.

Light-extraction enhancement of red AlGaInP light-emitting diodes with antireflective subwavelength structures

We demonstrate the enhancement of light extraction in 633 nm AlGaInP light-emitting diodes (LEDs) with antireflective subwavelength structures (SWS). From the contour plots by the rigorous coupled wave analysis method, it is found that the reduction of the internal reflection strongly depends on the period of SWS. The Ag nanoparticles formed by thermal dewetting were used as an etch mask for dry etch process to fabricate antireflective SWS on the LED surface. The tapered pillars on the GaP were fabricated, on average, with distances below 200 nm, satisfying the required antireflection condition at the emission wavelength. The improvement in light output power by approximately 26.4% was achieved for the fabricated AlGaInP LEDs with SWS compared to the conventional LEDs due to a strongly reduced Fresnel internal reflection at the GaP/air interface. The improved directionality in the far-field pattern was also obtained due to the directional light extraction enhancement.

Polyglycolic Acid-islet grafts improve blood glucose and insulin concentrations in rats with induced diabetes

Pancreatic islet transplantation is a promising therapeutic treatment for type 1 diabetes mellitus. In the present study, we cocultured islets with or without a polyglycolic acid (PGA) fibrous scaffold for 5 days and transplanted the PGA-islet grafts into the leg muscles of Wistar rats with streptozotocin-induced diabetes; controls were injected with saline. The results showed that the blood glucose concentrations of the group given islets embedded with the PGA scaffold were lower than those without the scaffold or controls. On the other hand, the insulin content of the PGA-islet group was higher at all 5 time points compared with the insulin contents of the other 2 groups. After transplantation, many islets in the PGA-islet grafts showed normal morphology (as seen under the scanning electron microscope) and were surrounded by red blood cells. A fibrous extracellular matrix was visible around the PGA-islet grafts. These results demonstrated that PGA-islet grafts improved blood glucose and insulin concentrations in rats with induced diabetes.

High-speed characteristics of vertical cavity surface emitting lasers and resonant-cavity-enhanced photodetectors based on intracavity-contacted structure

We fabricated vertical cavity surface emitting lasers (VCSELs) and resonant-cavity-enhanced photodetectors (RCE-PDs) with GaAs/AlGaAs distributed Bragg reflectors (DBRs), operating at lambda approximately 980 nm, based on an intracavity-contacted structure. The top-DBR mesa diameter of the VCSELs was optimized to 18 microm in terms of slope efficiency, differential series resistance, and 3 dB bandwidth. For VCSELs with an oxide aperture of 4.5 microm and a top-DBR mesa diameter of 18 microm, the threshold current was about 1.2 mA, exhibiting maximum output power of approximately 3.49 mW (at 20 degrees C) with good uniformity. The effect of the overetching in the outermost layer of RCE-PDs on the device performance was also investigated. For RCE-PDs based on the VCSEL structure, a peak responsivity of 0.44 A/W (at lambda approximately 979.7 nm) with a spectral width of approximately 3 nm and a dark current of 68 pA under a bias voltage of -5 V at 20 degrees C was obtained. The maximum 3 dB bandwidths of approximately 11.5 GHz with a modulation current efficiency factor of 5.6 GHz/mA(1/2) at -7 mA and 9 GHz at -7 V were achieved for VCSELs and RCE-PDs, respectively.

Adhesive growth of pancreatic islet cells on a polyglycolic acid fibrous scaffold

BACKGROUND

The use of cultured pancreatic islet cells for diabetes treatment offers several advantages. In theory, cultured cells show greater purity and lower immunogenicity. However, cultured islet cells display a low survival rate in vitro. In the present study we grew islet cells on a polyglycolic acid (PGA) fibrous scaffold to promote cell adhesion, growth, and viability during prolonged culture.

METHODS

Islets isolated from Wistar rat pancreata were digested with collagenase and purified by the Ficoll method. Cells were grown in culture with or without PGA scaffolds. Islet cell purity was determined using a dithizone stain; viability and survival rates were determined using an AO-PI stain. The insulin-secretion index was detected using radioimmunodetection and the growth on an adhesive scaffold analyzed using an inverted microscope and scanning electron microscope (SEM).

RESULTS

In contrast to the scaffold-free control group, cells cultured on PGA scaffolds exhibited improved morphology, less cell death, and prolonged survival times. Cell viability and survival rates were significantly increased in scaffolded cells when compared to control cells (P < .05). Increased insulin secretion was observed in the culture solution of scaffolded cells following stimulation with low glucose (5.6 mmol/L) versus high glucose (16.7 mmol/L). The secretion indices of the two groups were significantly different (P < .05). Islet cell growth, as observed under SEM, was tightly circumvolute, adhesive, and three-dimensional.

CONCLUSIONS

The present results demonstrated that islet cells can successfully grow and survive in culture on a PGA scaffold. These cells exhibited enhanced viability, survival, and insulin secretion.

Correlation of ventricular asymmetry with metabolic asymmetry in frontotemporal dementia

BACKGROUND AND PURPOSE

The clinical presentation of frontotemporal dementia (FTD) is often asymmetrical in terms of both its clinical features and atrophy on MRI. Asymmetry in the lateral ventricle size on structural neuroimaging in FTD patients may have clinical significance. However, this has not been systematically investigated yet. This study compares the ventricular asymmetry seen on MRI with that of the asymmetric glucose metabolism using FDG-PET in patients with FTD.

METHODS

Nineteen FTD patients who underwent both brain MRI and FDG-PET were retrospectively selected. As control groups, 23 and 11 age and sex-matched healthy normal subjects underwent either brain MRI or FDG-PET, respectively. The ventricular asymmetry index (VAI) was obtained in two ways: by visual rating (VAI-V) and by measuring the lateral ventricular volumes (VAI-ROI). The hemispheric asymmetry of the glucose metabolism on FDG-PET (MAI) was assessed in three ways: 1) by visual rating (MAI-V), 2) by counting the FDG activity of each hemisphere on normalized and smoothed PET images (MAI-ROI) and 3) by counting the number of voxels with significant hypometabolism based on statistical parametric mapping results (MAI-SPM).

RESULTS

The VAIs on MRI (VAI-V and VAI-ROI) were highly correlated, as were the MAIs (MAI-V, MAI-ROI, and MAI-SPM) on FDG-PET. More importantly, the VAIs on MRI and the MAIs on FDG-PET showed high correlation.

CONCLUSIONS

Ventricular asymmetry in FTD patients was common (78.9%) and there was a high correlation between the ventricular structural asymmetry and the hemispheric metabolic asymmetry. Therefore, it would be reasonable to interpret that the hemisphere with larger ventricle on MRI in FTD patients is undergoing a more active degenerative process.

Trends in socio-economic differentials in cigarette smoking behaviour between 1990 and 1998: a large prospective study in Korean men

OBJECTIVES

To investigate the magnitude and time trends in socio-economic differentials in cigarette smoking behaviour.

STUDY DESIGNS

A prospective observational study of male civil servants followed-up for 8 years.

SETTING

All civil service offices in Korea.

PARTICIPANTS

A total of 322,991 male civil servants aged 30-49 years on whom information on monthly salary was available and who had reported cigarette smoking behaviour between 1990 and 1998.

RESULTS

Smoking prevalence was 60.1% in 1990 and was inversely associated with salary level. The difference in smoking prevalence between the highest and the lowest salary groups gradually widened from 13.0% in 1990 to 16.1% in 1998. The relative index of inequality (RII) as a measure of socio-economic inequality in smoking behaviour was 1.91 [95% confidence interval (CI) 1.86-1.97] in 1990 and increased between 1990 and 1998. The RII for smoking cessation was 0.60 in 1990 (95% CI 0.58-0.62) and gradually decreased as time lapsed.

CONCLUSIONS

An increasing trend in socio-economic inequality in smoking behaviour was observed in this study.

Effects of selected minerals on leptin secretion in streptozotocin-induced hyperglycemic mice

The effects of lithium, magnesium, vanadate, and zinc on leptinemia and leptin secretion by adipose tissue were investigated in streptozotocin- (STZ) induced hyperglycemic mice. After the administration of studied minerals in drinking water for 4 weeks, fasting serum leptin concentrations were elevated, accompanied by normoglycemia in STZ-injected mice, regardless which mineral was provided (P < 0.05). However, the in vitro administration of lithium, magnesium, and vanadate did not significantly influence the leptin secretion of adipose tissue. A low zinc treatment (0.1 mM) augmented, whereas both a pharmacological treatment of zinc (1 mM) and zinc depletion (1 mM TPEN) attenuated, leptin secretion (P < 0.05). The present study shows that STZ-induced hyperglycemic mice have hypoleptinemia and reduced leptin secretion by adipose tissue. Moreover, these defects can be improved by a moderate zinc administration.

[Use of intraoperative red blood cell salvage in the anterior stabile operation of spinal fracture]

OBJECTIVE

To observe the clinical results in the anterior stabile operation of spinal fracture using red blood salvage.

METHODS

Nineteen cases with spinal fracture were performed the anterior decompress operation. Blood cell salvage were used during operation. Other 20 cases were also reviewed as control group, who were received the same operation without blood cell salvage.

RESULTS

In the 19 cases, average volume of autologous transfusion was 536 ml. Only two cases had homologous transfusion requirements. In the control group, all cases needed homologous transfusion (averaged 947 ml).

CONCLUSION

In the anterior decompress operation, the intraoperative blood salvage is highly effective in reducing transfusion and also improves the security of operation.

Body mass index and mortality: a twelve-year prospective study in Korea

The relation between body mass index (kg/m2) and noncoronary mortality is not well established. To study this relation, a population with low coronary mortality may be especially useful. We conducted a 12-year follow-up study of 235,398 Korean men 40-64 years of age. Study subjects had undergone health examinations in 1986 (baseline) and 1990. We excluded subjects with substantial weight loss during this period. There were 13,387 deaths, including 600 deaths from coronary events, between 1990 and 1998. We estimated the relation of body mass index to the risk of death after adjusting for common risk factors. There was a positive relation between body mass index and coronary mortality, but this relation was attenuated after serum total cholesterol, blood pressure, and fasting serum glucose were taken into account. A J-shaped relation with cerebrovascular mortality was also attenuated after adjustment. Even after this adjustment and exclusion of early deaths between 1990 and 1994, the relation of body mass index to all-cause (U-shaped), cancer (J-shaped), and noncancer noncoronary noncerebrovascular (inverse J-shaped) mortality remained. Both high and low body mass index were related to increased mortality among these Korean men.

Acute biochemical variations induced by calcium citrate and calcium carbonate in Type 2 diabetic patients: impaired calcium absorption in Type 2 diabetic patients with prolonged gastric emptying time

Calcium supplementation is important in the treatment of osteoporosis, a disease that may also occur in diabetic patients. The acute effects of calcium supplementation and their relationship to gastric emptying time, however, have rarely been studied in type 2 diabetic patients. We evaluated the acute biochemical variations induced by the administration of two different calcium preparations, calcium citrate and calcium carbonate, in 16 (male/female: 13/3) Chinese diabetic patients. Serum free calcium, intact parathyroid hormone (i-PTH), and amount of urinary excretion of calcium (uCal/uCr) were evaluated after a single dose of 1200 mg of elemental calcium in each preparation. The free calcium levels did not change significantly in either group. However, significant suppression of i-PTH after calcium citrate administration at 1 h (17.1+/-2.0 pg/ml, P=.023), and after calcium carbonate administration at 2 h (14.2+/-2.5 pg/ml, P=.000), was noted when compared with individual basal level (21.2+/-2.5 and 19.3+/-2.4 pg/ml, respectively). The suppressive effect on i-PTH lasted for 6 h after calcium citrate and 5 h after calcium carbonate preparation of the 6-h study period. After administration of calcium citrate, the uCal/uCr of 2-to-4-h collection was significantly higher than that of the basal and 0-to-2-h collections: 0.25+/-0.04 vs. 0.19+/-0.03, P=.025; and 0.25+/-0.04 vs. 0.19+/-0.02, P=.014, respectively. A similar finding was observed for calcium carbonate: 0.23+/-0.03 vs. 0.18+/-0.02, P=.019; and 0.23+/-0.03 vs. 0.18+/-0.02, P=.011, respectively. We conclude that, in this group of Chinese type 2 diabetic patients in our study, the oral administration of 1200 mg elemental calcium in either calcium citrate or calcium carbonate preparation can induce a significant suppression of i-PTH. This may be helpful in preventing or treating osteoporosis. A prolonged gastric emptying time in these diabetic subjects may contribute to the non-significant alteration in free calcium levels after the administration of either calcium preparation.

Short-term safety and tolerability of antihypertensive agents in Korean patients: an observational study

PURPOSE

In order to assess the short-term safety and tolerability of newly prescribed antihypertensive monotherapies in Korean patients, a prospective study was carried out.

METHODS

A total of 1181 patients were observed from July 1997 to August 1999. At 2, 4, 8 and 12 weeks after initiation of antihypertensive monotherapy, the patients were evaluated for whether treatment was to be continued and the development of any adverse reactions.

RESULTS

During the first 12 weeks, the percentage of subjects continuing with their initial angiotensin converting enzyme inhibitors (ACEI) (40.7%) was substantially lower than that of subjects continuing with angiotensin II receptor antagonists (ARA) (66.2%), alpha-blockers (63.0%), calcium channel blockers (CCB) (61.3%), beta-blockers (55.8%), and diuretics (53.5%), respectively (P < 0.01). The following adverse reactions were detected: cough (7.5%), headache (6.1%), dizziness (3.9%), flushing (3.7%) and impotence (2.4%). Cough, headache, and flushing were more frequent in women, and impotence and loss of libido were more frequent in men (P < 0.05). The incidence of cough associated with ACEI (27.9%) was higher than that associated with the other classes of drugs (P < 0.01).

CONCLUSIONS

The tolerability of antihypertensive medication was highest in Korean patients treated with ARAs, followed by CCBs, beta-blockers, diuretics, alpha-blockers, and ACEIs. The incidences of adverse reactions were different by sex, age and drug class.

Plasma concentrations of leptin and selected minerals do not differ in Type 2 diabetic patients with or without sulfonylurea inefficacy

The oral hypoglycemic agent sulfonylurea (SU) can increase plasma leptin concentrations. Additionally, diabetic subjects frequently have an altered plasma status of selected minerals. However, whether these described plasma parameters are changed in Type 2 diabetic patients who exhibit SU inefficacy has not yet been evaluated. In this preliminary study, fasting blood samples were collected from 16 Type 2 diabetic patients with secondary SU failure. As controls, 16 sex-, age- and adiposity-matched diabetic patients, who had similar diabetic duration and optimal glycemic control by SU, were also recruited. The results show that plasma values of leptin, C-peptide, calcium, magnesium, copper, and zinc did not significantly differ in these diabetic patients with or without secondary SU failure. However, the gender effect on plasma leptin level and the correlations between leptin and adiposity and C-peptide were retained. This study indicates that there is no relation between SU inefficacy and the plasma status of leptin and selected minerals.

Effect of zinc on cellular levels of calmodulin and cyclic adenosine monophosphate in the adipocyte

A perturbation of zinc metabolism has been noted in subjects with obesity. Zinc may also participate in the intracellular signal cascade by affecting cellular calcium influx and a change in the calcium-calmodulin (CaM)-cyclic adenosine monophosphate (cAMP) pathway. The possible effects of zinc on cellular concentrations of CaM, a major cytosolic calcium-binding protein, in the adipocytes derived from obese (ob/ob) mice and their lean counterparts were studied. Adipocytes derived from both phenotypes of mice were treated either with 0.2 mM of zinc sulfate or without any additive for 1 h of incubation; the cellular levels of CaM and cAMP were then determined. The results showed that the obese mice had lower CaM and cAMP levels in their adipocytes compared to the lean mice. Zinc treatment reduced CaM and increased cAMP levels in all mice, although this effect was more pronounced in the lean mice. This study indicated that there was an inverse interaction between CaM and cAMP in their cellular levels in the mouse adipocytes and that might be affected by exogenous zinc addition.

Methylprednisolone increases plasma leptin levels in Graves' hyperthyroidism patients with active Graves' ophthalmopathy

Whether leptin, a product of the ob gene, can be stimulated by glucocorticoid administration has been an issue of controversy. We investigated the effect of intravenous administration of methylprednisolone (500 mg/day x 3 days) on plasma levels of leptin in 16 patients (female/male = 11/5) with Graves' hyperthyroidism and active ophthalmopathy who received pulse therapy. Significant elevation of plasma leptin levels started at the eighth hour (13.9+/-1.8 ng/mL, p=0.042) and lasted until the 72nd hour (21.2+/-5.0 ng/mL, p=0.009), as compared with basal levels (8.8+/-1.2 ng/mL). When methylprednisolone was replaced with oral prednisolone (10 mg three times per day x 2 weeks), no difference in plasma leptin levels was noted compared with basal measurement. Under methylprednisolone administration, a significant suppression of tumor necrosis factor-alpha began at the 24th hour (8.1+/-1.3 pg/mL, p=0.004) and lasted until the 48th hour (8.1+/-1.0 pg/mL, p=0.008), as compared with basal measurement (12.5+/-1.5 pg/mL). Compared with basal levels (93+/-2 mg/dL), significant elevation in the plasma glucose level started at the third hour (135+/-10 mg/dL, p=0.000) and lasted until the 72nd hour (110+/-4 mg/dL, p=0.019). The timing of serum insulin elevation approximated that of plasma glucose (3 hours: 14+/-3 microU/mL, p=0.006) and lasted until the end of prednisolone administration (2 weeks: 12+/-2 microU/mL, p=0.044), when compared with basal levels (14+/-3 microU/mL). We concluded that the parental administration of pharmacological doses of methylprednisolone to patients with Graves' hyperthyroidism could acutely raise their plasma level of leptin.

Tertiary hyperparathyroidism in X-linked hypophosphatemic rickets

We report a case of tertiary hyperparathyroidism in an X-linked familial hypophosphatemic rickets (XLH) patient under regular calcitriol and self-adjusted large doses of oral phosphate salt (2.4-3.6 g/day in 4-5 divided doses) according to his serum phosphate level. Tertiary hyperparathyroidism is an unusual complication of XLH patients during treatment. As there is growing evidence that a high phosphate diet may induce hyperplasia of the parathyroid glands, it is important to avoid the stimulation of the parathyroid glands by high doses of phosphate administration in XLH patients. Serum calcium, phosphate, alkaline phosphatase, and also parathyroid hormone should be measured regularly in order to facilitate an early diagnosis of secondary hyperparathyroidism during the treatment of XLH patients, since this stage is reversible with calcitriol and reduced doses of phosphate salt.

Zinc may be a mediator of leptin production in humans

Obese individuals have hyperleptinemia and hypozincemia. Moreover, leptin and zinc have circadian changes in circulating concentrations. We investigated their possible interaction and examined whether a difference existed between obese men and their lean controls. The results indicated the pattern of circadian change in plasma zinc and leptin did not markedly differ between the obese subjects and the lean controls. However, the obese had higher leptin and lower zinc plasma values at each sampling time than did the lean controls. Because an inverse correlation was found in plasma values between zinc and leptin (r=-0.51, p=0.012), we further determined the role zinc might play in leptin production by human subcutaneous adipose tissue from female donors. The in vitro study showed that zinc treatment (0.2 mmol/L) significantly increased leptin production (142%), however, this increment did not surpass that by insulin (10 nmol/L). The data of this study suggest an interactive connection between zinc and leptin.

Which cholesterol level is related to the lowest mortality in a population with low mean cholesterol level: a 6.4-year follow-up study of 482,472 Korean men

To evaluate the relation between low cholesterol level and mortality, the authors followed 482,472 Korean men aged 30-65 years from 1990 to 1996 after a baseline health examination. The mean cholesterol level of the men was 189.1 mg/100 ml at the baseline measurement. There were 7,894 deaths during the follow-up period. A low cholesterol level (<165 mg/100 ml) was associated with increased risk of total mortality, even after eliminating deaths that occurred in the first 5 years of follow-up. The risk of death from coronary heart disease increased significantly in men with the highest cholesterol level (> or =252 mg/100 ml). There were various relations between cholesterol level and cancer mortality by site. Mortality from liver and colon cancer was significantly associated with a very low cholesterol level (<135 mg/100 ml) without any evidence of a preclinical cholesterol-lowering effect. With lengthening follow-up, the significant relation between a very low cholesterol level (<135 mg/100 ml) and mortality from stomach and esophageal cancer disappeared. The cholesterol level related with the lowest mortality ranged from 211 to 251 mg/100 ml, which was higher than the mean cholesterol level of study subjects.

Pituitary tumor cosecreting thyrotropin and prolactin causing hyperthyroidism--a case report

We report a case of a pituitary tumor cosecreting thyrotropin and prolactin with clinical manifestation of thyrotoxicosis, which is a very rare clinical disorder. Octreotide therapy is effective in suppressing the secretion of thyrotropin, prolactin, and thyroid hormones, and by this, renders relief of symptoms and complications of thyrotoxicosis.

Effect of acarbose administration on plasma concentrations of zinc and copper in patients with NIDDM

Acarbose reduces the intestinal absorption of dietary carbohydrate, thereby ameliorating postprandial hyperglycemia in diabetes mellitus. Dietary carbohydrate can modulate the bioavailability of some trace minerals like zinc and copper. Deficiencies in these minerals are associated with glucose intolerance. It is still unknown whether acarbose's reduction of intestinal carbohydrate absorption causes the short supply of these minerals. Thus, we investigated the changes in plasma zinc and copper levels in patients with NIDDM, after administration of acarbose for 3 months. The results showed that acarbose did not significantly affect fasting and postprandial plasma levels of these minerals, even after acarbose withdrawal. This study indicated that acarbose administration in NIDDM patients over a 3-month period does not influence plasma levels of zinc or copper.

Determination of proteins by fluorescence quenching of Magdala Red

Magdala Red (MR) binding to protein causes a decrease in the fluorescence intensity of MR at 556 nm. Based on this, a new quantitative determination method for proteins is developed. The linear range of this assay is 0.1-4.0 microg ml(-1) of Bovine Serum albumin (BSA). The measurements can be made easily on a common fluorimeter. The reaction between MR and proteins is completed in 1 min, and the fluorescence intensity is stable for at least 2 h. There is little or no interference from amino acids and most metal ions. The proposed method has been applied to the determination of protein in milk powder and soybean milk powder and the results are in agreement with the results by the other methods.

Excess mortality from avoidable and non-avoidable causes in men of low socioeconomic status: a prospective study in Korea

STUDY OBJECTIVE

The objective of this study was to evaluate the magnitude and contributory factors of socioeconomic differentials in mortality in a cohort of Korean male civil servants.

DESIGN

A prospective observational study of male civil servants followed up for five years after baseline measurement.

SETTING

All civil service offices in Korea.

PARTICIPANTS AND MEASUREMENTS

The study was conducted on 759,665 Korean male public servants aged 30-64 at baseline examination in 1992. The grade of monthly salary of these participants divided into four groups, a proxy indicator of socioeconomic status (SES), was the main predictive variable. Mortality of the participants was followed up from 1992 to 1996. The causes of deaths were categorised into four groups according to the medical amenability: avoidable, partly avoidable, non-avoidable, and external causes of death. The risk of mortality associated with SES was estimated using the Cox proportional hazard model.

MAIN RESULTS

Lowest SES group had significantly higher risk of mortality from most causes compared with the highest SES group in the order of external cause (relative risk (RR): 2.26), avoidable (RR: 1.65), all cause (RR: 1.59), and non-avoidable mortality (RR: 1.54). With the adjustment of known risk factors, significantly higher risks of mortality in lowest SES group were attenuated but persisted. Looking at the deaths from partly avoidable causes, significantly higher risks of mortality in the lowest SES group was observed from cerebrovascular disease but not from coronary heart disease.

CONCLUSIONS

Socioeconomic differentials in non-avoidable as well as avoidable mortality, persisting even under the control of risk factors, suggest that mortality is influenced not only by the quality of health care and different distribution of risk factors but also by other aspects of SES that are yet unknown.

Zinc effects on hyperglycemia and hypoleptinemia in streptozotocin-induced diabetic mice

Zinc has an antihyperglycemic effect. Zinc can also influence the production of leptin, a satiety factor that reduces appetite and blood sugar level. In this study, we investigated the effect of zinc supplementation on food intake and circulating leptin and glucose concentrations in streptozotocin-induced diabetic mice. Male diabetic mice received zinc supplementation (20 ppm) from drinking water for two weeks. The results showed that zinc treatment did not affect body weight gain, body fat content or food intake in these diabetic mice. However, zinc supplementation markedly ameliorated the hyperglycemia of diabetic mice. After zinc treatment, serum leptin concentrations tended to increase in the diabetic mice. This study suggests that zinc is a mediator of leptin production.