Palm tocotrienol exerted better antioxidant activities in bone than alpha-tocopherol

The aim of this study was to investigate the effects of vitamin E on the levels of lipid peroxidation and antioxidant enzymes in rat bones. Fifty-six normal male Sprague-Dawley rats, aged 3 months, were randomly divided into seven groups with eight rats in each group. The age-matched control group was given the vehicle olive oil, by oral gavage daily. Six of the treatment groups received either palm tocotrienol or pure alpha-tocopherol at the dose of 30, 60 or 100 mg/kg body weight, by oral gavage daily, 6 days a week for 4 months. Thiobarbituric acid-reactive substance (TBARS) that is an index to measure the level of lipid peroxidation and the antioxidant enzymes, glutathione peroxidase and superoxide dismutase levels were measured in the femur at the end of the study. Palm tocotrienol at the dose of 100 mg/kg body weight significantly reduced the TBARS level in the femur with a significant increase in glutathione peroxidase activity compared to the age-matched control group. These were not observed in the alpha-tocopherol groups. Palm tocotrienol was more effective than pure alpha-tocopherol acetate in suppressing lipid peroxidation in bone. Palm tocotrienol showed better protective effect against free radical damage in the femur compared to alpha-tocopherol. This study suggests that palm tocotrienol plays an important role in preventing imbalance in bone metabolism due to free radicals.     

Restoration of proximal periprosthetic bone loss by denosumab in cementless total hip arthroplasty

Summary

Denosumab contributed to the restoration of proximal periprosthetic bone loss around the femoral stem that were measured using a DEXA, especially in zone 7, at 1 year after cementless THA in elderly osteoporotic patients.

Introduction

Although bone quality is an important issue in elderly osteoporotic patients who underwent total hip arthroplasty (THA) with a cementless stem, periprosthetic bone mineral density (BMD) in the proximal femur has been reported to be decreased by 15–40% postoperatively. Some authors have examined the use of several types of bisphosphonates to prevent decreases in BMD in the proximal femur after cementless THA; however, few reports have demonstrated success in restoring BMD in the proximal medial femoral bone, such as zone 7.

Methods

We conducted prospective study comparing patients who underwent cementless THA administered with denosumab (10 patients) and without denosumab (10 patients). BMD around the femoral stem were measured using a DEXA immediately after surgery, and at 6 months and at 1 year after surgery. No difference was found between the two groups referred to the patient’s demographic data.

Results

We found that denosumab displayed definitive effects in increasing the % change in periprosthetic BMD at zone 7 by an average of 7.3% in patients with cementless THA, compared to control group who were given only vitamin D.

Conclusion

Denosumab is one of a number of anti-osteoporotic agents to have a definitive effect on the restoration of proximal periprosthetic bone loss, especially in zone 7, after cementless THA. Denosumab contributed to the restoration of decreased periprosthetic BMD to normal levels. As the decrease in BMD in the proximal femur after THA is considered to be apparent at 6–12 months after surgery, it is believed that prevention of the deterioration of bone quality is important in the proximal femur immediately after cementless THA for elderly female patients with osteoporosis.

     

Linking land-use and land-cover transitions to their ecological impact in the Amazon

Human activities pose a major threat to tropical forest biodiversity and ecosystem services. Although the impacts of deforestation are well studied, multiple land-use and land-cover transitions (LULCTs) occur in tropical landscapes, and we do not know how LULCTs differ in their rates or impacts on key ecosystem components. Here, we quantified the impacts of 18 LULCTs on three ecosystem components (biodiversity, carbon, and soil), based on 18 variables collected from 310 sites in the Brazilian Amazon. Across all LULCTs, biodiversity was the most affected ecosystem component, followed by carbon stocks, but the magnitude of change differed widely among LULCTs and individual variables. Forest clearance for pasture was the most prevalent and high-impact transition, but we also identified other LULCTs with high impact but lower prevalence (e.g., forest to agriculture). Our study demonstrates the importance of considering multiple ecosystem components and LULCTs to understand the consequences of human activities in tropical landscapes.

Tropical forests host two-thirds of all terrestrial biodiversity (1), account for one-third of terrestrial productivity and evapotranspiration (2), and store half of all terrestrial carbon (3, 4). Despite their global importance, tropical forests are being severely affected by human activities (5). Deforestation is a key driver of change—more than 100 million ha of primary tropical forests have been converted to agriculture and silviculture in the last 40 y (6, 7). Many of the remaining primary forests are also degraded. Between 2000 and 2005 at least 20% of tropical forests were selective logged (8), while other anthropogenic drivers and extreme droughts are increasing forest fires, with 54 million ha burned annually in the 1990s (9). Even deforested landscapes are changing; agricultural abandonment is a key driver of secondary forest regrowth, and now these forests account for at least half of all tropical forests globally (10), including 28% of deforested land in the Amazon (11). Other areas are undergoing agricultural intensification, with pastures being converted to croplands (12, 13). Hence, many tropical landscapes are now a mosaic of nonforested land uses, regenerating secondary forests, and variably degraded primary forests (14).Several studies have quantified the different land-use and land-cover transitions (LULCTs) in tropical forest regions, including in the Amazon (e.g., refs. 15 and 16). We know, for example, that conversion of forests to pastures and degradation of primary forests are the main LULCTs in the Amazon (15, 16), while secondary forest recovery is still very limited compared with deforestation (11). In addition, the value of human-modified tropical landscapes has been examined in detail for above-ground carbon storage (17), soil condition (18), vegetation structure (19), and biodiversity (20). The ecological literature shows that conversion transitions, for example deforestation, are expected to cause the greatest impact on forest ecosystems (21), but degradation of primary forests can also be as harmful as deforestation for biodiversity when it occurs at scale (22). Other studies discuss how fast biodiversity and carbon can recover in regenerating secondary forests, suggesting, for example, that up to 80% of primary forest tree species could be present in 40-y-old Amazonian secondary forests (23), while a meta-analysis suggests that, even after a century, plant species diversity does not recover to undisturbed tropical forest levels (24).Although the scientific community has been building a solid knowledge base on LULCTs in tropical forest regions, the existing studies do not reveal the full extent of changes in landscape condition for four key reasons: First, a compilation of the rates of different types of LULCTs, including deforestation, regeneration, and forest degradation, is still lacking, impeding a comprehensive view of LULCT dynamics that allows a quantitative comparison between all transitions. Second, region-specific studies often focus on one or two ecosystem components (24–26) or compare changes with an undisturbed forest baseline rather than evaluating the full range of transitions (23, 27). Third, meta-analyses have focused on 1) a single ecosystem component (18), 2) a single type of LULCT (28), or 3) comparing all changes with an undisturbed baseline, without exploring the transitions that occur between human-modified land uses (21). Finally, ecological changes have not been linked to prevalence (e.g., measured as annual rates) of the land-cover transitions to date. Quantifying transitions in terms of prevalence and impact on ecosystem properties is a key step toward understanding the relative importance of changes across whole landscapes and could provide evidence-based scenarios for policymakers to decide how to better protect and benefit from tropical forest biodiversity and ecosystem services.Here, we quantified the prevalence and the ecological impacts of 18 LULCTs in the Brazilian Amazon to make a comprehensive assessment of the relative risk of the major LULCTs. We focused on the following questions: 1) What are the rates of LULCTs? 2) What are the impacts of LULCTs on different ecosystem properties (e.g., biodiversity, carbon, and soil)? 3) Which transitions impose the greatest magnitude of change on the ecosystem? Ecological data encompassed 18 variables sampled at 310 sites in two distinct regions of the Brazilian Amazon, which we grouped into three ecological dimensions that reflect policy or management levers: biodiversity (vascular plants, birds, and three invertebrate groups), carbon pools, and soil properties. These ecosystem components were surveyed in seven land-use or land-cover classes: undisturbed primary forest, logged primary forest, logged-and-burned primary forest, old secondary forest (>20 y since abandonment), young secondary forest (≤20 y old), pasture, and mechanized agriculture. The impacts of 18 LULCTs on ecosystem variables were then assessed against the annual LULCT rates estimated between 2006 and 2014 (29) or 2006 and 2019 (15), providing an understanding of both the magnitude and extent of changes in land use and land cover in the Brazilian Amazon.     

Socioeconomic Factors and Vitamin A Status of Pregnant Women in Calabar Urban,Southeastern Nigeria

Vitamin A deficiency (VAD) is prevalent in developing countries. Socioeconomic status is increasingly being associated with nutritional status of individuals. Efforts to control or eliminate VAD must focus on socioeconomic factors and how to tackle them in the midst of other well recognized strategies. This research sought to determine the socioeconomic factors that may affect the serum retinol levels of pregnant women in Calabar, Nigeria. A total of 101 pregnant women in Calabar were studied for the effect of socioeconomic factors on the maternal vitamin A status using a structured household questionnaire and biochemical analytical techniques. The study revealed that a majority (82.2%) of the women studied were in their normal reproductive years (20–45 years), 63.4% had previous childbirth experience, 89.1% had formal education, 85% were employed, 85% lived in medium to large families (4 persons and above) while 62.3% were in the middle or high income class (over N50,000 per month). Among the women, only 35.6% had adequate vitamin A status while the rest had deficient (15.8%), low (32.7%) or very high (15.8%) levels. The results of the analysis of the influence of socioeconomic characteristics of the women on serum retinol status showed a positive relationship between serum retinol level and education (P < 0.05; F = 2.84) and between serum retinol level and parity (P < 0.05; F = 2.05). Serum retinol concentration was not affected by age, occupation, household size and other household characteristics used in the study. Increased maternal education and appropriate child spacing may be the key strategies for the elimination and control of vitamin A deficiency in developing countries.     

Effects of Nicotine Administration and Nicotine Cessation on Bone Histomorphometry and Bone Biomarkers in Sprague–Dawley Male Rats

Nicotine is a major alkaloid of tobacco, which can increase free radical formation, leading to osteoporosis. The effects of nicotine administration and cessation on bone histomorphometry and biomarkers were studied in 28 Sprague–Dawley male rats. Rats aged 3 months and weighing 250–300 g were divided into four groups: control (C, normal saline for 4 months), nicotine for 2 months (N2), nicotine for 4 months (N4), and nicotine cessation (NC). The NC group was given nicotine for the first 2 months and then allowed to recover for the following 2 months without nicotine. Histomorphometric analysis was done using an image analyzer. ELISA kits were used to measure serum osteocalcin (bone formation marker) and pyridinoline (PYD, bone resorption marker) levels at month 0, month 2, and month 4. All test groups showed a significant decrease in BV/TV, Ob.S/BS, dLS/BS, MAR, BFR/BS, and osteocalcin levels and an increase in sLS/BS and PYD levels compared to group C. No significant differences were observed in all parameters measured among the test groups, except for MAR and BFR/BS. In conclusion, nicotine administration at a dose of 7 mg/kg for 2 and 4 months has detrimental effects on bone metabolism. Nicotine administration at 7 mg/kg for 2 months is sufficient to produce significant effects on bone histomorphometric parameters and biomarkers. In addition, prolonging the treatment for another 2 months did not show any significant differences. Cessation of nicotine for 2 months did not reverse the effects.     

Histomorphometric changes in the perirenal adipocytes of adrenalectomized rats treated with dexamethasone

INTRODUCTION:

Prolonged steroid treatment administered to any patient can cause visceral obesity, which is associated with metabolic disease and Cushing''s syndrome. Glucocorticoids have a profound negative effect on adipose tissue mass, giving rise to obesity, which in turn is regulated by the 11β-hydroxysteroid dehydrogenase type 1 enzyme. Adrenalectomized rats treated with dexamethasone exhibited an increase in visceral fat deposition but not in body weight.

OBJECTIVES:

The main aim of this study was to determine the effect of dexamethasone on the histomorphometric characteristics of perirenal adipocytes of adrenalectomized, dexamethasone-treated rats (ADR+Dexa) and the association of dexamethasone treatment with the expression and activity of 11β-hydroxysteroid dehydrogenase type 1 (11β- hydroxysteroid dehydrogenase type 1).

METHODS:

A total of 20 male Sprague Dawley rats were divided into 3 groups: a baseline control group (n = 6), a sham-operated group (n = 7) and an adrenalectomized group (n = 7). The adrenalectomized group was given intramuscular dexamethasone (ADR+Dexa) 2 weeks post adrenalectomy, and the rats from the sham-operated group were administered intramuscular vehicle (olive oil).

RESULTS:

Treatment with 120 µg/kg intramuscular dexamethasone for 8 weeks resulted in a significant decrease in the diameter of the perirenal adipocytes (p<0.05) and a significant increase in the number of perirenal adipocytes (p<0.05). There was minimal weight gain but pronounced fat deposition in the dexamethasone-treated rats. These changes in the perirenal adipocytes were associated with high expression and dehydrogenase activity of 11β-hydroxysteroid dehydrogenase type 1.

CONCLUSIONS:

In conclusion, dexamethasone increased the deposition of perirenal fat by hyperplasia, which causes increases in the expression and dehydrogenase activity of 11β-hydroxysteroid dehydrogenase type 1 in adrenalectomized rats.     

Tocotrienol supplementation in postmenopausal osteoporosis: evidence from a laboratory study

OBJECTIVE:

Accelerated bone loss that occurs in postmenopausal women has been linked to oxidative stress and increased free radicals. We propose the use of antioxidants to prevent and reverse postmenopausal osteoporosis. This study aimed to examine the effects of tocotrienol, a vitamin E analog, on bone loss due to estrogen deficiency. Our previous study showed that tocotrienol increased the trabecular bone volume and trabecular number in ovariectomized rats. In the current study, we investigated the effects of tocotrienol supplementation on various biochemical parameters in a postmenopausal osteoporosis rat model.

MATERIALS AND METHODS:

A total of 32 female Wistar rats were randomly divided into four groups. The baseline group was sacrificed at the start of the study, and another group was sham operated. The remaining rats were ovariectomized and either given olive oil as a vehicle or treated with tocotrienol at a dose of 60 mg/kg body weight. After four weeks of treatment, blood was withdrawn for the measurement of interleukin-1 (IL1) and interleukin-6 (IL6) (bone resorbing cytokines), serum osteocalcin (a bone formation marker) and pyridinoline (a bone resorption marker).

RESULTS:

Tocotrienol supplementation in ovariectomized rats significantly reduced the levels of osteocalcin, IL1 and IL6. However, it did not alter the serum pyridinoline level.

CONCLUSION:

Tocotrienol prevented osteoporotic bone loss by reducing the high bone turnover rate associated with estrogen deficiency. Therefore, tocotrienol has the potential to be used as an anti-osteoporotic agent in postmenopausal women.     

Direct aspiration first pass technique for a middle cerebral artery occlusion with a hidden aneurysm

Hidden aneurysms within occluded vessels present a challenge for interventionists because vessel perforation can lead to life-threatening complications. We present a case of middle cerebral artery ischemic stroke, refractory to thrombolysis. A direct aspiration first pass technique (ADAPT) was employed for revascularization. Following thrombectomy, an aneurysm of the occluded vessel was revealed. Despite this, the patient recovered without hemorrhagic complication. ADAPT permits the minimal insertion of endovascular devices and might be a safe procedure when hidden aneurysms are suspected.