Does immediate loading of a single implant in the healed anterior maxillary ridge improve the aesthetic outcome compared to conventional loading?

BACKGROUND: Immediate loading is an attractive option for avoiding secondary surgery. However, it is unclear whether it provides a better aesthetic outcome compared to conventional loading with implants placed in healed ridges. AIMS: To compare the aesthetic outcomes of immediately and conventionally loaded single implants in healed anterior maxillary ridges. METHODOLOGY: A systematic review using PICO was conducted. EMBASE, MEDLINE and DoSS databases were searched. The Cochrane Risk of Bias tool for Randomised Controlled Trials and the Effective Public Health Practice Project tool for other study designs were used for quality appraisal. A narrative synthesis was undertaken. RESULTS: A total of 622 articles were identified. After screening, a total of five papers were included. Results indicated no statistically significant difference in pink or white aesthetic scores between the immediate and conventional loading groups at 1- and 5-year review and the Papilla Index at the 1-year review. CONCLUSION: Within the limitations of this review, immediate loading of single implants provides a comparable aesthetic outcome to conventional loading in healed ridges of the anterior maxillary.

Effect of thymectomy on the female reproductive cycle in neonatal guinea pigs.

OBJECTIVE: The appropriate function of the hypothalamic-pituitary-gonadal axis is essential for maintaining proper reproductive function. In female mammals, the hypothalamic-pituitary-gonadal axis regulates reproductive changes that take place in the estrus cycle and are necessary for successful reproduction. This study was conducted to investigate the effect of thymectomy on the estrus cycle in neonatally thymectomized guinea pigs. METHODS: In this study, 12 female guinea pigs, six thymectomized and six sham-operated, were studied. The effects of neonatal thymectomy at 5-7 days of age on parameters of the reproductive axis were examined in female guinea pigs. Gonadotropin and 17ß-estradiol levels were assessed at regular intervals (days 0, 3, 6, 9, 12, and 15) of the estrus cycle, and the time of vaginal opening in the thymectomized and shamoperated guinea pigs was determined. RESULTS: Significant reductions in gonadotropins and 17ß-estradiol levels during estrus cycle were found in neonatally thymectomized female guinea pigs compared to sham-operated guinea pigs. CONCLUSION: The results of this study underscore the importance of the thymus in the neonatal period for normal female reproductive function.

Effects of osteoarthritis on load transfer after cemented total shoulder arthroplasty.

BACKGROUND: Total shoulder arthroplasty is commonly performed to treat glenohumeral osteoarthritis (OA); however, little is understood of the mechanics of the reconstructed OA shoulder. We sought to establish the effects of OA-induced changes in bone density and retroversion angle on load transfer and stress distribution in the bone-implant system of the scapula. METHODS: We developed finite element models of reconstructed healthy and OA scapulas with a virtually implanted glenoid prosthesis design. For the OA scapula, models with uncorrected and corrected retroversion were created. Loads were applied at the center or posteriorly on the glenoid surface. RESULTS: Our results suggest that with reconstruction of the corrected glenoid with a contemporary implant, cement stresses increase and the load transfer pattern changes with eccentric loads. The load transfer and local stresses in the bone-implant system in the retroverted glenoid are less sensitive to changes in loading location. Furthermore, the load transfer in the OA glenoid is less sensitive to the effect of peg proximity to the cortical shell than in the healthy glenoid. CONCLUSION: We provided evidence of how load sharing is altered among healthy, corrected OA, and retroverted OA glenoids. We demonstrated that correction of retroversion in OA glenoids may actually increase the risk for stress shielding and cement failure compared with retroverted glenoids, and OA patients can accommodate shorter pegs because of the higher glenoid bone stiffness in the OA glenoid.

VEGF and eNOS expression in umbilical cord from pregnancy complicated by hypertensive disorder with different severity.

BACKGROUND: Reduced blood flow in hypertensive pregnancy may influence the production vasoconstrictors; subsequently the vessel remains in highly contracted state. NO is a vasodilator; VEGF influences its synthesis by regulating eNOS production. Aim of our study was to evaluate the expression of VEGF and eNOS in different severity of hypertensive pregnancy. METHODS: Study was conducted in 4 groups with 40 members: group 1--control, group 2--gestational hypertension, group 3--mild preeclampsia, and group 4--severe preeclampsia. Fetal end of umbilical cord was taken and follows IHC staining protocol for VEGF and eNOS antibody. Staining intensity were measured by semiquantitative scoring method. Mann Whitney U test was used to compare each group. RESULTS: Decreased expression of both VEGF and eNOS was found in hypertensive condition than in normal condition. Among hypertensive group, severe preeclamptic group showed more intensity in staining than gestational hypertension and mild preeclampsia. CONCLUSION: Reduction of VEGF and eNOS in gestational hypertension may lead to hypoperfusion and subsequent hypoxia of fetus in hypertensive pregnancy. The developed hypoxic state may upregulate the synthesis of VEGF and thereby eNOS. Increased expression of VEGF and eNOS in severe group may be a compensatory mechanism to dilate the blood vessels and to improve blood flow of fetus.

Nonconforming glenoid increases posterior glenohumeral translation after a total shoulder replacement.

BACKGROUND: The major complication in nonconforming total shoulder replacement (TSR) is glenoid loosening and is attributed to posteriorly directed humeral head translations. Whether the posterior translations observed clinically are induced by radial mismatch is unclear. The objective of our study was to explain the posterior glenohumeral translations observed clinically after TSR by determining the glenohumeral translation and contact force as a function of radial mismatch. We hypothesized that the posterior direction of glenohumeral translation during scaption would be related to the radial mismatch and that the joint contact force would increase as the radial mismatch increased. METHODS: A 6-degrees-of-freedom computational model of the glenohumeral joint was developed. We determined the muscle forces, joint contact force, and glenohumeral translation for radial mismatches from 1 mm to 20 mm with the shoulder positioned from 20° to 60° of scaption. RESULTS: As the radial mismatch increased, the contact location of the humeral head moved posteriorly and inferiorly. The middle deltoid force decreased by 3%, while the supraspinatus and infraspinatus muscle forces increased by 9% and 11%, respectively. The joint contact force remained relatively constant. CONCLUSIONS: Increased posterior glenohumeral translations were observed with increased radial mismatch. Clinical observations of posterior translation may be attributed to the balancing forces of the middle deltoid, infraspinatus, and supraspinatus muscles. High radial mismatches may lead to eccentric posterior loading on the glenoid component, which could lead to implant loosening and failure.

Promising anti-diabetes mellitus activity in rats of ß-amyrin palmitate isolated from Hemidesmus indicus roots.

While evaluating the toxicity of the tuberous root extracts of Hemidesmus indicus, a traditional medicinal plant, the glucose lowering property of the root was observed by the investigators. Therefore, it was thought of interest to isolate the anti-hyperglycemic principle from the root and determine its utility to develop an anti-diabetes mellitus medicine. The active principle was isolated from H. indicus root extract by anti-hyperglycemic activity guided chromatographic techniques. Glucose tolerance test in rats was used to evaluate the anti-hyperglycenic property. Anti-diabetes mellitus property was evaluated in alloxan-induced diabetic rats as well as streptozotocin-induced (type-2 model) diabetic rats. The active principle was isolated and identified with spectral data as ß-amyrin palmitate. Although it is a known compound, its presence in H. indicus is not known previously. It was observed for the first time that ß-amyrin palmitate has remarkable anti-hyperglycemic activity in orally glucose loaded rats. Further, interestingly, it exhibited excellent anti-diabetes mellitus activity in both alloxan-diabetic and streptozotocin-diabetic rats at a very low concentration (50µg/kg body weight). One of the mechanisms of action of ß-amyrin palmitate appears to be blocking the entry of glucose from the intestine. ß-Amyrin palmitate is very promising to develop a medicine for diabetes for combination therapy and/or mono-therapy.

Load transfer after cemented total shoulder arthroplasty.

BACKGROUND: Glenoid loosening is the primary reason for failure after a total shoulder arthroplasty (TSA), but the failure mechanism is not yet known. This study determined how the load transfer and stress distribution are affected by the introduction of a glenoid implant. METHODS: We developed a finite-element model of a scapula with and without a virtually implanted modern glenoid prosthesis design. Two load magnitudes were considered: normal and high. Loading locations were simulated at the center and at 4 eccentric positions on the glenoid. A metal-backed implant was also simulated to understand the effect of fixation stiffness. RESULTS: In the intact glenoid, for both center and eccentric loading, the majority of stress was distributed in the cancellous bone, whereas after a reconstruction, stresses in that region were lower. Metal-backed implants further decreased the joint load carried by the bone. Stresses in the cement layer increased during eccentric and high-magnitude loading. CONCLUSION: This study provided a basic understanding of the load-sharing phenomenon after a TSA that could explain glenoid loosening failure. Our results suggest that with reconstruction of the glenoid with a contemporary implant, the load transfer pattern is significantly altered, with eccentric and high-magnitude loads increasing stresses in the cement indicating potential for failure. The use of a metal-backed implant reduces the load carried by the bone, which may be detrimental to long-term TSA survival.

Bringing the state back in: understanding and validating measures of governments' political commitment to HIV.

Analysis of the politics of HIV programme scale-up requires critical attention to the role of the state, since the state formulates HIV policies, provides resources for the HIV response and negotiates donor involvement in HIV programmes. However, conceptual and methodological approaches to analysing states' responses to HIV remain underdeveloped. Research suggests that differences in states' successes in HIV programme scale-up reflect their levels of 'political commitment' to responding to HIV. Few empirical measures of political commitment exist, and those that do, notably the AIDS Program Effort Index (API), employ ad hoc scoring approaches to combine information from different variables into an index of commitment. The indices are thus difficult to interpret and may not have empirically useful meaning. In this paper, we apply exploratory factor analysis to examine whether, and how, selected variables that comprise the API score reflect previously theorised dimensions of political commitment. We investigate how variables associated with each of the factors identified in the analyses correspond to these theorised dimensions as well as to API categories. Finally, we discuss potential uses--such as political benchmarking and accountability--and challenges of factor analysis as a means to identify and measure states' political commitment to respond to HIV.

A novel aphrodisiac compound from an orchid that activates nitric oxide synthases.

Nitric oxide (NO) is known to have roles in several crucial biological functions including vasodilation and penile erection. There are neuronal, endothelial and inducible NO synthases that influence the levels of NO in tissues and blood. NO activates guanylate cyclase and thereby increases the levels of cyclic GMP (cGMP). Viagra (sildenafil), a top selling drug in the world for erectile dysfunction, inhibits phosphodiesterase-5, which hydrolyses cGMP to GMP. Thus, it fosters an NO-mediated increase in the levels of cGMP, which mediates erectile function. Here, we show the aphrodisiac activity of a novel chemical isolate from the flowers of an epiphytic orchid, Vanda tessellata (Roxb.) ex Don, which activates neuronal and endothelial, but not inducible, NO synthases. The aphrodisiac activity is caused by an increase in the level of NO in corpus cavernosum. The drug increases blood levels of NO as early as 30 min after oral administration. The active compound was isolated by column chromatography. Based on the spectral data, the active compound is found to be a new compound, 2,7,7-tri methyl bicyclo [2.2.1] heptane. We anticipate that our findings could lead to the development of a commercially viable and valuable drug for erectile dysfunction.

Indicators of political commitment to respond to HIV.

OBJECTIVES: National political commitment is likely to become particularly crucial to sustaining antiretroviral treatment programmes in the coming decade, as donor contributions to HIV funding decreases. The objective of this study is to synthesise information on existing indicators of political commitment to respond to national HIV epidemics. METHODS: The authors describe and critically evaluate the existing indicators and propose studies to validate them. RESULTS: Several indicators have been developed to measure governments' political commitment to respond to national HIV epidemics--the AIDS Program Effort Index, the United Nations General Assembly Special Session on HIV/AIDS Declaration of Commitment Indicators and the AIDS Policy Aggressiveness Indicators--but the validity of these measures has not been systematically assessed. The indicators differ in their intended use, collection methods, content categories, data coverage, and strengths and limitations. Several types of studies could be used to test indicator validity (based on indicator content, comparisons of the same indicator using different elicitation methods, relationship patterns between indicators, relations between indicators and other variables and the consequences of using the indicators). CONCLUSIONS: The existing indicators of political commitment to respond to national HIV epidemics are useful for many purposes, including research, policymaking and advocacy. A range of studies could improve the understanding of indicator validity. New data collection and measurement approaches offer opportunities to improve how actors in the HIV community capture the complicated, multidimensional concept of political commitment.

Conceptual and methodological challenges to measuring political commitment to respond to HIV.

BACKGROUND: Researchers have long recognized the importance of a central government's political "commitment" in order to mount an effective response to HIV. The concept of political commitment remains ill-defined, however, and little guidance has been given on how to measure this construct and its relationship with HIV-related outcomes. Several countries have experienced declines in HIV infection rates, but conceptual difficulties arise in linking these declines to political commitment as opposed to underlying social and behavioural factors. METHODS: This paper first presents a critical review of the literature on existing efforts to conceptualize and measure political commitment to respond to HIV and the linkages between political commitment and HIV-related outcomes. Based on the elements identified in this review, the paper then develops and presents a framework to assist researchers in making choices about how to assess a government's level of political commitment to respond to HIV and how to link political commitment to HIV-related outcomes. RESULTS: The review of existing studies identifies three components of commitment (expressed, institutional and budgetary commitment) as different dimensions along which commitment can be measured. The review also identifies normative and ideological aspects of commitment and a set of variables that mediate and moderate political commitment that need to be accounted for in order to draw valid inferences about the relationship between political commitment and HIV-related outcomes. The framework summarizes a set of steps that researchers can follow in order to assess a government's level of commitment to respond to HIV and suggests ways to apply the framework to country cases. CONCLUSIONS: Whereas existing studies have adopted a limited and often ambiguous conception of political commitment, we argue that conceiving of political commitment along a greater number of dimensions will allow researchers to draw a more complete picture of political commitment to respond to HIV that avoids making invalid inferences about the relationship between political commitment and HIV outcomes.

Patterns of tropomyosin and troponin-T isoform expression in jaw-closing muscles of mammals and reptiles that express masticatory myosin.

We recently reported that masticatory ('superfast') myosin is expressed in jaw-closing muscles of some rodent species. Most mammalian limb muscle fibers express tropomyosin-ß (Tm-ß), along with fast-type or slow-type tropomyosin-ß (Tm-ß), but jaw-closing muscle fibers in members of Carnivora express a unique isoform of Tm [Tm-masticatory (Tm-M)] and little or no Tm-ß. The goal of this study was to determine patterns of Tm and troponin-T (TnT) isoform expression in the jaw-closing muscles of rodents and other vertebrate species that express masticatory myosin, and compare the results to those from members of Carnivora. Comparisons of electrophoretic mobility, immunoblotting and mass spectrometry were used to probe the Tm and fast-type TnT isoform composition of jaw-closing and limb muscles of six species of Carnivora, eight species of Rodentia, five species of Marsupialia, big brown bat, long-tailed macaque and six species of Reptilia. Extensive heterogeneity exists in Tm and TnT isoform expression in jaw-closing muscles between phylogenetic groups, but there are fairly consistent patterns within each group. We propose that the differences in Tm and TnT isoform expression patterns between phylogenetic groups, which share the expression of masticatory myosin, may impart fundamental differences in thin-filament-mediated muscle activation to accommodate markedly different feeding styles that may require high force generation in some species (e.g. many members of Carnivora) and high speed in others (e.g. Rodentia).

Antibacterial Screening of Aegle Marmelos; Lawsonia Inermis and Albizzia Libbeck

Three medicinal plant Aegle marmelos; Lawsonia inermis; Albizzia libbeck were extracted by soxhlet apparatus using petroleum ether; ethanol; chloroform and aqueous as solvent. Among those extract; the petroleum ether was considered as effective one. The extracts were subjected to preliminary phytochemical screening and the three plants with four extracts were tested against three Gram positive bacteria (B.cereus; B.subtilis; S. aureus) and three Gram negative bacteria (E.coli; P.vulgaris; and P.aeruginosa) by disc diffusion method. Maximum inhibition (3.8cm) was recorded in Lawsonia inermis. It also showed inhibitory action against all the six pathogen tested. The zone of inhibition of the extracts was compared with the standard antibiotics Streptomycin and Spectinomycin. The study suggests that the plant is promising the development of phytomedicine for antimicrobial properties

Antibacterial screening of Aegle marmelos, Lawsonia inermis and Albizzia libbeck.

Three medicinal plant Aegle marmelos, Lawsonia inermis, Albizzia libbeck were extracted by soxhlet apparatus using petroleum ether, ethanol, chloroform and aqueous as solvent. Among those extract, the petroleum ether was considered as effective one. The extracts were subjected to preliminary phytochemical screening and the three plants with four extracts were tested against three gram positive bacteria (B. cereus, B. subtilis, S. aureus) and three gram negative bacteria (E. coli, P. vulgaris, and P. aeruginosa) by disc diffusion method. Maximum inhibition (3.8 cm) was recorded in Lawsonia inermis. It also showed inhibitory action against all the six pathogen tested. The zone of inhibition of the extracts was compared with the standard antibiotics Streptomycin and Spectinomycin. The study suggests that the plant is promising the development of phytomedicine for antimicrobial properties.