Association of Weight Trajectory With Severe Obesity: A Case-Control Study

Background: Early childhood weight trajectory is associated with future risk for obesity. However, little is known about the association of birth weight and weight trajectories before age 5.5 years with severe adult obesity. Methods: This study used a nested case-control design of 785 matched sets of cases and controls matched 1:1 on age and gender from a 1976 to 1982 birth cohort in Olmsted County, Minnesota. Cases with severe adult obesity were defined as individuals with a BMI ≥40 kg/m2 after 18 years of age. There were 737 matched sets of cases and controls for the trajectory analysis. Weight and height data from birth through 5.5 years were abstracted from the medical records, and weight-for-age percentiles were obtained from the CDC growth charts. Results: A two-cluster weight-for-age trajectory solution was identified as optimal, with cluster 1 having higher weight-for-age before age 5.5 years. While there was no association between birth weight and severe adult obesity, the odds of being in cluster 1, which includes children with higher weight-for-age percentiles, was significantly increased for cases compared with controls [odds ratio (OR) 1.99, 95% confidence interval (CI) 1.60-2.47]. The association between cluster membership and case-control status persisted after adjusting for maternal age and education (adjusted OR 2.08, 95% CI 1.66-2.61). Conclusions: Our data suggest that early childhood weight-for-age trajectories are associated with severe obesity status in adult life. Our results add to growing evidence that it is critical to prevent excess early childhood weight gain.

Atrial fibrillation care improvement collaborative

Atrial fibrillation (AF) is an increasingly common cardiac arrhythmia. Many patients with new onset or recurrent AF present to the emergency department and are subsequently admitted to the hospital and seen by cardiology specialists for follow up. In an attempt to address this high utilization of acute health care resources, reduce costs, and improve patient care, our institution instituted a collaborative project between the departments of emergency medicine, cardiology, family medicine, and primary care internal medicine.

The project team oversaw development of a new emergency department AF order set, encouraged utilization of a new oral anticoagulant (dabigatran), improved the primary care follow up connection, and deployed a multimodal education plan for primary care providers. Between 2012 and 2014, these interventions resulted in a 17% reduction in total AF per member per month (PMPM) cost, a 28% reduction in AF PMPM inpatient cost, and a 24% reduction in inpatient admissions for AF.

Differential effects of reduced cyclic stretch and perturbed shear stress within the arterial wall and on smooth muscle function

BACKGROUND

Cyclic circumferential stretch and shear stress act in concert and yet are capable of independently mediating arterial smooth muscle function, modulating the production of superoxide and stimulating arterial remodeling.

METHODS

Porcine carotid arteries were perfused ex vivo for 72 h. Groups combining normal (5%) and reduced (1%) stretch with high shear (6 +/- 3 dyn/cm2) and oscillatory shear (0.3 +/- 3 dyn/cm2) stress were created, while maintaining a pulse pressure of 80 +/- 10 mm Hg.

RESULTS

Total superoxide production, fibronectin expression, and gelatinase activation were mediated by shear stress, but expression in the endothelial region was mediated by reduced cyclic stretch. By plotting intensity vs. radius, we saw that superoxide and gelatinase activity were in part mediated by stress distributions throughout the vascular wall, whereas fibronectin and p22-phox were much less or not at all. These findings, when coupled with our results from tissue reactive studies, suggest that the arterial remodeling process triggered in the endothelial region due to reduced stretch causes the most significant changes in arterial smooth muscle function.

CONCLUSIONS

We have found that the remodeling process triggered by reduced compliance in the endothelial region of large conduit arteries has a more profound detrimental effect to smooth muscle function than that brought on by perturbed shear stress. This work provides new insight by suggesting that although mechanical stimuli such as cyclic stretch and shear stress are known to augment similar markers of vascular remodeling, the location of their expression throughout the vascular wall differs greatly and this can have dramatic effects on vascular function.

Arterial biomechanics after destruction of cytoskeleton by Cytochalasin D

Vascular smooth muscle is a major structural element of the arterial wall. We examined the effects of cytoskeleton destruction, after administration of Cytochalasin D, on the biomechanical properties of porcine common carotids. Compared to untreated, maximally dilated controls, Cytochalasin D-treated arteries have shown a marked increase in compliance in the elastin-dominated pressure range. After weakening the VSM stress-bearing cytoskeleton by Cytochalasin D the artery would expand, reaching a new equilibrium state. This study brings further evidence that VSM is under tension, even when it is under zero load and at maximal vasodilation. This residual tension was released upon partial destruction of the cytoskeleton with Cytochalasin D. From a biomechanical standpoint, this means that the zero stress states of the in-series and parallel elastic components are substantially different.

Prevalence of HIV and other sexually transmissible infections in relation to lemon or lime juice douching among female sex workers in Jos, Nigeria

Background: The rates of sexually transmissible infections (STI), including HIV, are high among female sex workers (FSW) in Nigeria and the use of various local vaginal cleansing agents to prevent infection is a common practice. The present study was aimed at determining whether any association exists between current lime or lemon douching and the prevalence of STI and HIV infections among FSW in Jos, Nigeria. Methods: Consenting FSW who were users of lemon or lime (UL) or non-users (NUL) were recruited for the study between May and September 2006. A structured questionnaire was administered by trained counsellors. Pre-HIV test counselling was done. Participant’s blood samples were tested for HIV and syphilis. Genital examination was done and high vaginal and endocervical samples were collected. The samples obtained were processed for STI using standard laboratory procedures. FSW found with treatable STI received free drugs. HIV results were disclosed after post-test counselling and positive FSW were referred to a HIV/AIDS facility for care, support and antiretroviral therapy. Results: A total of 398 FSW (86 UL and 312 NUL) participated in the study. Their mean age was 27.6 ± 7.0 years (range 16–63 years). HIV prevalence was high for both UL and NUL: 48.8 and 48.2%, respectively (odds ratio 1.0; 95% confidence interval 0.6–1.2, P = 0.9427). The rates of bacterial vaginosis were not significantly higher in UL (UL 55.8%, NUL 44.0%, odds ratio 1.59, 95% confidence interval 0.96–2.65, P = 0.06). There were no associations between the use of citrus douching and other STI. Conclusion: There were no significant associations between the prevalence of STI and HIV and lime or lemon juice usage.

Oscillatory shear stress and reduced compliance impair vascular functions

Shear stress has been shown to influence endothelial cell gene expression and morphology. In particular, low and bi-directional shear stress, mimicking conditions at plaque-prone areas, down-regulates the expression of several atheroprotective genes, and up-regulates that of other genes considered as pro-inflammatory. Another mechanical situation thought to have a negative influence on vascular functions is arterial stiffness. Loss of arterial compliance occurs during ageing, in diabetic as well as in hypertensive patients. In this work we investigated the effects of these two particular hemodynamic environments (bi-directional shear stress and reduced compliance), using a recently developed perfusion system allowing to expose native arteries in vitro to complex hemodynamic environments. We were able to show that both plaque-prone shear stress and reduced compliance trigger endothelial dysfunction, but via different mechanisms. Only reduced compliance affected vascular contractility, inducing a dedifferentiation of smooth muscle cells and a consequent loss of norepinephrine sensitivity.

Sexual problems among married Nigerian women

We interviewed and examined 293 married women, 15-49 years of age, seeking primary care at a teaching hospital in central Nigeria. One or more sexual problems were identified in 71% of women. The proportion of specific sexual problems was 39% for a desire problem, 40% for an arousal problem, 31% for a sex pain problem and 55% for an orgasmic problem. Poor marital communication, lack of foreplay, Islamic religion and advancing age were independently associated with a desire problem. Absence of foreplay was independently associated with an arousal problem. Lack of foreplay, lower abdominal pain, gynaecological conditions, working outside the home and younger age were independently associated with a sex pain problem. The absence of foreplay, poor marital communication and being a housewife were independently associated with an orgasmic problem. Sexual problems are common among married Nigerian women seeking outpatient care.

An extensible and systematic force field, ESFF, for molecular modeling of organic, inorganic, and organometallic systems

ESFF is a rule-based force field designed for modeling organic, inorganic, and organometallic systems. To cover this broad range of molecular systems, ESFF was developed in an extensible and systematic manner. Several unique features were introduced including pseudoangle and a dot product function representing torsion energy terms. The partial atomic charges that are topology-dependent are determined from ab initio (DFT) calculated electronegativity and hardness for valence orbitals. The van der Waals parameters are charge-dependent, and correlated with the ionization potential for atoms in various valence states. To obtain a set of well-defined and physically meaningful parameters, ESFF employs semiempirical rules to translate atomic-based parameters to parameters typically associated with a covalent valence force field. The atomic parameters depend not only on atom type, but also on internal type, thus resulting in a more accurate force field. This article presents the theory and the method used to develop the force field. The force field has been applied to molecular simulations of a wide variety of systems including nucleic acids, peptides, hydrocarbons, porphyrins, transition metal complexes, zeolites, and organometallic compounds. Agreement with the experimental results indicates that ESFF is a valuable tool in molecular simulations for understanding and predicting both crystal and gas phase molecular structures.

Aminoaciduria in calcium-deficiency rickets in northern Nigeria

Generalized aminoaciduria is associated with vitamin D-deficiency rickets in humans, but there is little information regarding aminoaciduria in rickets caused by primary calcium deficiency. In contrast to rickets in other parts of the world, this bone disease in Nigeria is caused primarily by inadequate intake of dietary calcium. We conducted a clinical trial in Jos, Nigeria in 10 children with radiographically and biochemically proven rickets; an equal number of non-rachitic healthy children from the same area served as controls. Serum and 24 h urine samples were obtained at baseline and at 24 h, 1 week, 4 weeks, and 12 weeks after initiation of calcium supplementation (1000 mg/day) and were analysed for their content of amino acids. Serum calcium, phosphorus, intact parathyroid hormone (PTH), 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D were also measured at each time point. In the rachitic subjects urinary amino acid concentrations were elevated from 2- to 16-fold at baseline, while serum amino acid levels increased 1.5- to 3.8-fold compared to controls. After 12 weeks of calcium supplementation, serum and urine amino acids decreased. There was no correlation between the degree of aminoaciduria and serum PTH or 1,25-dihydroxyvitamin D concentrations. We conclude that the aminoaciduria in these rachitic children was related to their calcium status and not to their vitamin D or PTH status.

Rickets in Nigerian children: response to calcium supplementation

In a previous study of rachitic children in Jos, Nigeria we concluded that inadequate dietary intake of calcium was the primary contributing factor to the development of their rickets. The objective of the present study was to determine the effect of calcium supplementation in 10 children with radiographically and biochemically proven rickets from the same geographical area. Rachitic children were provided with calcium supplements of 1000 mg/day for a period of 3 months. Serum and urine samples were obtained at baseline and at 24 hours, 1 week, 4 weeks, and 12 weeks after initiation of supplementation. Serum calcium, phosphorus, alkaline phosphatase, intact parathyroid hormone, 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D were measured at each time point. Dietary recalls obtained at two separate times were used to estimate usual daily intakes of calcium and phosphorus. Ten non-rachitic age-matched controls from the same geographical area were recruited for comparison. Nine of 10 rachitic subjects had radiographic evidence of healing after 3 months of calcium therapy. Although serum calcium concentrations returned to control levels, other biochemical data indicated that the rickets of these subjects may have been multifactorial in aetiology, pointing to a possible defect in the synthesis of 25-hydroxyvitamin D.

Calcium supplements increase the serum levels of crosslinked N-telopeptides of bone collagen and parathyroid hormone in rachitic Nigerian children

OBJECTIVES

Biochemical markers of bone turnover were measured in the sera of 16 controls and 10 children with calcium-deficiency rickets, during a 12-week course of calcium supplementation (1 g CaCO3/d) that was effective in healing the bone lesions of the rachitic children.

DESIGN AND METHODS

Serum levels of crosslinked N-telopeptides of bone collagen (NTx), parathyroid hormone (PTH), alkaline phosphatase (ALP), and urinary deoxypyridinoline (LP) were assayed at baseline and during the course of calcium therapy and compared with data of the 16 non-rachitic controls.

RESULTS

Calcium therapy suppressed serum NTx and PTH levels in the rachitic children within 24 h; however, after the first week, PTH and NTx levels increased to the extent that at 12 weeks both were elevated when compared with controls or to baseline levels. Serum levels of NTx and PTH were correlated in the controls and experimental subjects (r = 0.63, p < 0.001).

CONCLUSIONS

The rate of bone resorption, as estimated by serum NTx concentration, is increased during the healing of rachitic lesions.

Parametric sensitivity analysis of avian pancreatic polypeptide (APP)

Computer simulations utilizing a classical force field have been widely used to study biomolecular properties. It is important to identify the key force field parameters or structural groups controlling the molecular properties. In the present paper the sensitivity analysis method is applied to study how various partial charges and solvation parameters affect the equilibrium structure and free energy of avian pancreatic polypeptide (APP). The general shape of APP is characterized by its three principal moments of inertia. A molecular dynamics simulation of APP was carried out with the OPLS/Amber force field and a continuum model of solvation energy. The analysis pinpoints the parameters which have the largest (or smallest) impact on the protein equilibrium structure (i.e., the moments of inertia) or free energy. A display of the protein with its atoms colored according to their sensitivities illustrates the patterns of the interactions responsible for the protein stability. The results suggest that the electrostatic interactions play a more dominant role in protein stability than the part of the solvation effect modeled by the atomic solvation parameters.

A hybrid approach to theoretical analysis of bovine pancreatic trypsin inhibitor

A static analysis of bovine pancreatic trypsin inhibitor (BPTI) is presented based on a new discrete/continuum approach to modeling the dynamics of biomolecules. This hybrid method utilizes knowledge of the intramolecular potential and molecular configuration to generate a field of elastic modulus tensors. These tensors, which relate the local stress and strain for each atom in the biomolecule, can be used to judge the local rigidity as well as indicate regions of high stress. Comparing the tensor fields for an unrelaxed and a relaxed configuration, the microscopic structure of BPTI is found to be anisotropic and to have regions of stress even when it is relaxed in the potential field. However, when these fields are averaged over the whole protein or over individual residues the structure becomes more isotropic and the stressed regions vanish. Using these averaged tensors, we calculated bulk properties such as Young's modulus and the Lamé constants and they agreed with previously reported values.

Arginine-rich histones do not exchange between human and mouse chromosomes in hybrid cells

Following division of HeLa-3T3 heterokaryons, human and mouse chromosomes occupy distinct regions within the resulting hybrid nuclei. This favorable orientation of genomes has allowed us to determine whether histones exchange between chromosomes in vivo. Acrylamide gel electrophoresis of the proteins from HeLa cells labeled with 3H-arginine during S phase showed that the core histones were labeled preferentially, constituting 30% of the total cellular tritium and 50% of the label in a crude nuclear fraction. Autoradiographic analysis of cells formed by fusion of 3H-arginine-labeled HeLa cells and 3T3-4E cells showed that 3H-arginine-labeled proteins did not migrate between nuclei in heterokaryons; hybrid cells formed from such heterokaryons contained nuclei in which 3H proteins occupied a sector within the nucleus; "sectored nuclei" could persist for at least 4 days; and the unequal distribution of 3H proteins did not change during DNA synthesis. Electron microscopic examination of hybrid nuclei failed to reveal a physical partition between human and mouse chromosome sets. Sectored nuclei were also observed in synkaryons derived from 3H-arginine-labeled HeLa and unlabeled HeLa cells, indicating that the unequal distribution of 3H-arginine-labeled proteins in HeLa-3T3 hybrid cells did not result from species-specific binding of proteins and DNA. The persistent unequal distribution of 3H-arginine-labeled proteins within hybrid nuclei in the apparent absence of a barrier between mouse and human chromosomes indicates that histones, the principal 3H-arginine-labeled proteins do not dissociate from DNA in vivo.

Degradation of proteins microinjected into cultured mammalian cells

Iodinated proteins were degraded after injection into HeLa cells at first-order rates with half-lives varying from three hours for the trout monhistone chromosomal protein, HMG-T, -to 60 hours for whale myoglobin. Fluoresceinated-bovine serum albumin (fl-BSA) was degraded almost twice as fast as unmodified BSA. The rate of degradation of 125I-BSA was very similar in eight cell lines of mouse, human, monkey and rat origin. Microinjected proteins were analyzed on SDS-acrylamide gels after injection, and for BSA and immunoglobin G, all remaining intracellular 125I migrated at the molecular weight of the injected proteins. By contrasting, more than 80% of the extracellular 125I chromatographed as iodotyrosine. With the exception of fl-BSA, which exhibited perinuclear accumulation in approximately one-half of the injected cells, autoradiography showed that throughout the period of study the injected proteins remained dispersed in the cytoplasm.