Genetic regulation of growth from birth to 18 years of age: The Swedish young male twins study

Growth is a complex process, and only little is known on the genetic regulation of it. We analyzed the effect of genetic and environmental factors on growth in a longitudinal Swedish cohort of 231 monozygotic and 144 dizygotic twin pairs born 1973–1979 with length or height measured annually from birth to age 18. The data were analyzed by two different multivariate variance component models for twin data using the Mx statistical package. At birth and 1 year of age, a substantial part of the variation in length was because of common environment (50 and 57%, respectively) and the effect of genetic factors was minor. After 2 years of age, 91–97% of the variation of height could be explained by genetic differences whereas the rest was because of environmental variation not shared by twins. The genetic correlation between heights at ages 2 and 18 was 0.73 (95% confidence intervals 0.68–0.77) showing that 53% of the genes affecting height at these ages are the same or closely linked; with increasing age the correlation with genetic effects at age 18 become subsequently stronger. Especially in mid‐childhood, growth was largely regulated by the same genetic factors. During puberty new genetic factors started to affect height, but also genetic variation affecting height at previous ages remained. These results suggest that genetic regulation of growth is rather uniform, which is encouraging for further efforts to identify genes affecting growth. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.     

Methyl cellulose gel obstructed bone formation by GBR: an experimental study in rats

AIM: To evaluate whether bone formation under Teflon capsules may be enhanced by concomitant implantation of recombinant human platelet-derived growth factor-BB/insulin-like growth factor-I (rhPDGF-BB/IGF-I) incorporated into a methyl cellulose gel. MATERIALS AND METHODS: Fifty-five male 6-month-old albino rats of the Wistar strain were used in the study. The lateral aspect of the mandibular ramus was exposed on both sides of the jaw. In 70 sites, the periosteum was removed from the ramus, leaving the bone denuded, while in 35 sites, it was preserved. On 10 non-periosteal (P-) sites and five periosteal (P+) sites, an empty rigid teflon capsule (d=7 mm), serving as control, was placed on the ramus. In the 40 test animals, the capsule placed on the one side of the jaw was filled at random with one of three different concentrations (1,200, 600, 150 microg/ml) of rhPDGF-BB/IGF-I gel. The capsules placed on the contralateral side of the jaw contained a placebo methyl cellulose gel. Each growth factor group, defined according to the gel concentration, and the placebo group contained 10 capsules placed on the P- side and five capsules placed on the P+ side. Two months after surgery, all animals were sacrificed. RESULTS: Histologic analysis revealed that in the non-filled control capsules, the amount of new bone including the bone marrow was 29.9% and 39.7% of the capsule area on the P- and P+ sides, respectively. In the test capsules with the growth factor gel and placed on the P-sides, the amounts of new bone ranged from 5.6% to 6.3%, which were similar (p>0.05) to that formed in the capsules filled with the methyl cellulose gel (5.5%). New bone formation was larger in the capsules on the P+ sides than in those on the P- sides but was similar in the capsules with different growth factor concentrations (range 17.9-19.6%) and in those with placebo gel (21.0%). In all groups, the carrier gel was poorly absorbed and occupied most of the capsules. CONCLUSION: Local application of a methyl cellulose gel obstructed bone formation under Teflon capsules placed adjacent to uninjured cortical bone in the mandibular ramus of rats. These data suggest that another material should be utilized to deliver growth factors under Teflon membranes for guided bone regeneration.     

Impairments, disabilities and handicap pattern in konzo - a non-progressive spastic para/tetraparesis of acute onset

Purpose: To assess impairments, disabilities and handicap pattern in konzo.

Method: The study included 17 konzo subjects, of which three were males and 14 females (mean age 21, median 18 years). A detailed neurological examination was performed on all subjects. Subsequently, an assessment of impairments, disabilities and handicap was done with a constructed rating scale partially based on the ICIDH-2 framework.

Results: The overall disablement picture in all subjects consisted of motor dysfunction in lower limbs leading to limitations in walking and movement activities, and restrictions in mobility. Hip mobility was severely impaired in most cases (15/17). Although konzo subjects showed normal muscle power in upper limbs (13/17), they had impaired fine motor function (10/17).

Conclusion: Further studies are needed to assess the effectiveness of the WHO criteria for konzo in defining its forms. The applicability of the ICIDH-2 framework in this study demonstrates the possibility of its use as a common language among researchers in the field of motor disorders. However, a revision is suggested of its taxonomy, and a definition of operational criteria to clarify the content of different qualifiers provided to assess the level of functioning or disability.     

Meningeal metastasis of leiomyosarcoma mimicking meningioma: CT and MR findings

A case of leiomyosarcoma metastatic to the meninges is reported. The tumor had imaging features typical for meningioma on CT and postcontrast magnetic resonance.     

Tanzania national survey on iodine deficiency: impact after twelve years of salt iodation

Background  

In many low-income countries, children are at high risk of iodine deficiency disorders, including brain damage. In the early 1990s, Tanzania, a country that previously suffered from moderate to severe iodine deficiency, adopted universal salt iodation (USI) as an intervention strategy, but its impact remained unknown.     

Guided tissue regeneration using biodegradable membranes of polylactic acid or polyurethane

Abstract The purpose of the present investigation was to evaluate the use of biodegradable membranes of polylactic acid or polyurethane for obtaining regeneration following treatment of circumferential periodontal defects in monkeys with the “guided tissue regeneration” procedure. Orthodontic elastic bands were placed around selected test and control teeth in 4 monkeys in order to induce breakdown of the periodontal tissues. When the destruction of the supporting tissues had progressed to a level corresponding to approximately half the length of the roots, the elastic bands were removed. After 1 to 8 months, full thickness flaps were raised on the buccal and lingual aspects of both test and control teeth. The exposed root surfaces were scaled and a notch was prepared in the root surface at the level of the reduced bone crest. Membranes of polylactic acid or polyurethane were placed circumferentially around the test teeth, while no membranes were placed around the control teeth. The tissue flaps were then sutured in a coronally displaced position. The surgical procedures and sacrifice of the animals were scheduled to provide observation times of 1, 4 and 8 months. During the healing period, various complications such as recession of the flap margins and exposure or exfoliation of the membranes were noticed. The histological analysis showed that the amount of new connective tissue attachment on test and control teeth did not differ and was restricted to the most apical part of the lesions. The bio-degradable membranes could be identified in a few specimens, and they were always surrounded by an epithelial layer. This observation suggests that the membranes had been exfoliated rather than resorbed in the tissue. Although biodegradable membranes of polylactic acid or polyurethane failed to produce regeneration in the present study, such membranes should not be considered inapplicable in conjunction with the GTR-procedure. It is necessary, however, for these materials to be modified and transformed into a membrane which possesses all of the properties necessary for proper function.     

Novel variants in the putative peroxisome proliferator-activated receptor {gamma} promoter and relationships with obesity in men

Yet unidentified variants within the peroxisome proliferator-activated receptor gamma (PPARgamma) 2 promoter may explain the inconsistent reports on associations between variants in the coding region and obesity or diabetes. Thus, we examined the putative PPARgamma2 promoter (-3371 to +43 bp) for variants in 83 subjects with obesity or type 2 diabetes. We identified eight variants, seven of which were novel, including -792A>G, -816C>T, -882T>C, -1505G>A, -1881C>T, -1884T>A, -2604T>C, and -2953A>G. The variants -816C>T, -1505G>A, -1881C>T, and -2604T>C were in total linkage disequilibrium, and there was a high degree of linkage disequilibrium between several of the novel variants and Pro12Ala. The novel variants were, together with Pro12Ala and 1431C>T, examined for relationships with obesity among 234 men with early-onset obesity with a BMI at age approximately 20 years of 33.2+/-2.5 kg/m2 and 323 nonobese men with a BMI of 21.7+/-2.5 kg/m2, who were also reexamined after approximately 29 years. The prevalence of the identified variants was not significantly different between the two groups, and the variants did not affect changes in BMI over time. In conclusion, the identified novel variants in the PPARgamma2 promoter region do not explain the reported discrepancies in the association of previously identified variants with obesity and type 2 diabetes.     

The total lifetime health cost savings of smoking cessation to society

BACKGROUND: Smoking cessation has major immediate and long-term health benefits. However, ex-smokers' total lifetime health costs and continuing smokers' costs remain uncompared, and hence the economic savings of smoking cessation to society have not been determined. METHODS: The economic effects of smoking cessation in a lifetime perspective have been examined by comparing the health costs of continuing smokers and ex-smokers by quantity of daily tobacco consumption, age, gender and disease group, while taking differences in life expectancy and the reductions in relative risks after cessation into account. RESULTS: The total lifetime health cost savings of smoking cessation are highest at the younger ages. Although the economic savings vary with age at quitting, gender and quantity of daily tobacco consumption, all ex-smoking men and women who quit smoking at the age of 35 to 55 years generate sizeable total lifetime cost savings. At older ages, the total lifetime health cost savings of smoking cessation are of little economic consequence to the society. The total, direct and productivity lifetime cost savings of smoking cessation in moderate smokers who quit smoking at the age of 35 years are 24,800 euros, 7600 euros, and 17,200 euros in men, and 34,100 euros, 12,200 euros, and 21,800 euros in women, respectively. CONCLUSIONS: Lifetime health cost savings of smoking cessation to society are substantial at younger ages, in terms of both direct and productivity costs.     

Clinical evaluation of an enamel matrix derivative and a bioresorbable membrane in the treatment of degree III mandibular furcation involvement: a series of nine patients

The present study evaluated the effect of combining an enamel matrix derivative (EMD) and a bioresorbable membrane (GTR) in the surgical treatment of degree III mandibular furcation involvements. Nine patients with chronic periodontitis, presenting a total of 14 degree III mandibular furcation involvements, were included in the study. Surgical treatment of the defects was randomly assigned: (1) EMD (four defects); (2) GTR (three defects); and (3) EMD and GTR (seven defects). The degree of involvement was assessed prior to surgery and after 6 and 12 months by measuring the probing attachment level in the horizontal and vertical directions at the furcation site. At 6 and 12 months, partial closure of the involvements had occurred in approximately half of the treated furcations, and the vertical probing level consistently improved following all three treatment modalities. The results suggest that all three treatment modalities may improve healing following surgical treatment of degree III mandibular furcation involvements. However, further studies are needed to examine the clinical significance of these results and the histologic characteristics of the healing following application of EMD.