Hormonal factors in the development of differences in strength between boys and girls during adolescence: a longitudinal study

The mitochondrial transition pore (MTP) is implicated as a mediator of cell injury and death in many situations. The MTP opens in response to stimuli including reactive oxygen species and inhibition of the electron transport chain. Sporadic Parkinson's disease (PD) is characterized by oxidative stress and specifically involves a defect in complex I of the electron transport chain. To explore the possible involvement of the MTP in PD models, we tested the effects of the complex I inhibitor and apoptosis-inducing toxin N-methyl-4-phenylpyridinium (MPP+) on cyclosporin A (CsA)-sensitive mitochondrial swelling and release of cytochrome c. In the presence of Ca2+ and Pi, MPP+ induced a permeability transition in both liver and brain mitochondria. MPP+ also caused release of cytochrome c from liver mitochondria. Rotenone, a classic non-competitive complex I inhibitor, completely inhibited MPP(+)-induced swelling and release of cytochrome c. The MPP(+)-induced permeability transition was synergistic with nitric oxide and the adenine nucleotide translocator inhibitor atractyloside, and additive with phenyl arsine oxide cross-linking of dithiol residues. MPP(+)-induced pore opening and cytochrome c release were blocked by CsA, the Ca2+ uniporter inhibitor ruthenium red, the hydrophobic disulfide reagent N-ethylmaleimide, butacaine, and the free radical scavenging enzymes catalase and superoxide dismutase. MPP+ neurotoxicity may derive from not only its inhibition of complex I and consequent ATP depletion, but also from its ability to open the MTP and to release mitochondrial factors including Ca2+ and cytochrome c known to be involved in apoptosis.     

Early strabismus surgery for thyroid ophthalmopathy

OBJECTIVE: To determine whether strabismus surgery during active thyroid ophthalmopathy is beneficial for selected patients. DESIGN: Case series. PARTICIPANTS: Eight patients with severe restrictive strabismus due to thyroid ophthalmopathy underwent early strabismus surgery and were followed for a minimum of 16 months after their initial surgery. INTERVENTION: All eight patients underwent strabismus surgery while their thyroid ophthalmopathy was evolving. MAIN OUTCOME MEASURES: Success was determined by the ability to fuse in the primary position at distance and near without an abnormal head position, and the absence of vision-threatening complications related to strabismus surgery. RESULTS: All eight patients achieved successful long-term alignment. Four patients (50%) required more than one operation. CONCLUSIONS: Strabismus surgery during active thyroid ophthalmopathy can result in long-term stable alignment and may be a useful alternative in selected patients with marked disability due to thyroid ophthalmopathy.     

Age-related differences in management of heart disease: a study of cardiac medication use in an older cohort. Pacemaker Selection in the Elderly (PASE) Investigators

Bone mass, bone metabolic markers, and calcium regulation hormones were measured in members of an Antarctic wintering team who stayed at the Japanese Antarctic station, Syowa (latitude: south 69 degrees 00', longitude: east 39 degrees 35') for 1 year. Subjects included 31 healthy Japanese males, aged 24-51 years (mean age 34.5 years) at the beginning of this study, ingesting 488 IU/day of vitamin D and 550.9 mg/day of calcium per person. The long-term coefficient of variation (CV) of the equipment used in the assessments of bone mass was 0.67% in single X-ray absorptiometry (SXA), 0.17% in the speed of sound (SOS) by quantitative ultrasound method (QUS), and 0.63% in broadband ultrasound attenuation (BUA) by QUS. The seasonal changes in the calcaneal bone mineral density (BMD) by SXA were not significant, whereas the SOS measured by QUS decreased during the measurement period (0.55%, p < 0.001), and BUA increased (1.9%, p < 0.01). Bone-specific alkaline phosphatase and osteocalcin levels increased significantly during summer (p < 0.001) and urinary calcium level decreased significantly during winter (p < 0.05). Urinary pyridinoline and deoxypyridinoline levels decreased significantly at the end of winter (p < 0.001). Serum 1,25(OH)2D3 level did not change significantly, whereas serum 25(OH)D3 level decreased significantly during winter (p < 0.001). Serum parathyroid hormone (PTH) level significantly increased at the end of winter (p < 0.01), although both PTH level and 25(OH)D3 level remained within the normal range. We concluded that the 25(OH)D3 level in subjects who stayed in Antarctica for 1 year decreased significantly with the reduction in duration of sunshine, but there were no clear changes in bone mass.     

Dietary amino acids as new and novel agents to enhance allograft survival

Little is known about the long-term effects of fluoride-releasing materials on carious dentine in vivo. The aim was to investigate the 2-year influence of a resin-modified glass ionomer cement (RM-GIC) and amalgam on the bacteriological counts of carious dentine that remained under class I restorations. To enable a split-mouth design, 33 molar pairs in 33 patients (mean age 15.1 years, SD 1.4) were selected, based on clinically and radiographically diagnosed occlusal dentine caries. The enamel of the carious molars was removed, and the carious dentine was sampled under aseptic conditions just beneath the dentinoenamel junction. The molars were alternately restored with RM-GIC or amalgam without further removal of carious dentine. The samples were processed for microbiological determination of total viable counts (TVC), mutans streptococci (MS), and lactobacilli (LB). The molar pairs of 25 patients were reevaluated after 2 years using the same clinical techniques and were permanently restored after complete caries removal. Both materials showed a substantial decrease in numbers of TVC and LB of the carious dentine after the 2-year period. Compared to amalgam, the decrease in the numbers of LB was significantly more pronounced for RM-GIC. No microorganisms were detected in only 11 molars (6 RM-GIC and 5 amalgam) after the 2-year period. Based on this study, we suggest that complete removal of carious dentine is still the best conservative treatment, irrespective of the restorative material used.     

Increased dietary oxalate does not increase urinary calcium oxalate saturation in hypercalciuric rats

BACKGROUND: Human calcium oxalate (CaOx) nephrolithiasis may occur if urine is supersaturated with respect to the solid-phase CaOx. In these patients, dietary oxalate is often restricted to reduce its absorption and subsequent excretion in an effort to lower supersaturation and to decrease stone formation. However, dietary oxalate also binds intestinal calcium which lowers calcium absorption and excretion. The effect of increasing dietary oxalate on urinary CaOx supersaturation is difficult to predict. METHODS: To determine the effect of dietary oxalate intake on urinary supersaturation with respect to CaOx and brushite (CaHPO4), we fed 36th and 37th generation genetic hypercalciuric rats a normal Ca diet (1.2% Ca) alone or with sodium oxalate added at 0.5%, 1.0%, or 2.0% for a total of 18 weeks. We measured urinary ion excretion and calculated supersaturation with respect to the CaOx and CaHPO4 solid phases and determined the type of stones formed. RESULTS: Increasing dietary oxalate from 0% to 2.0% significantly increased urinary oxalate and decreased urinary calcium excretion, the latter presumably due to increased dietary oxalate-binding intestinal calcium. Increasing dietary oxalate from 0% to 2.0% decreased CaOx supersaturation due to the decrease in urinary calcium offsetting the increase in urinary oxalate and the decreased CaHPO4 supersaturation. Each rat in each group formed stones. Scanning electron microscopy revealed discrete stones and not nephrocalcinosis. X-ray and electron diffraction and x-ray microanalysis revealed that the stones were composed of calcium and phosphate; there were no CaOx stones. CONCLUSION: Thus, increasing dietary oxalate led to a decrease in CaOx and CaHPO4 supersaturation and did not alter the universal stone formation found in these rats, nor the type of stones formed. These results suggest the necessity for human studies aimed at determining the role, if any, of limiting oxalate intake to prevent recurrence of CaOx nephrolithiasis.     

Framing as a theory of media effects

Research on framing is characterized by theoretical and empirical vagueness. This is due, in part, to the lack of a commonly shared theoretical model underlying framing research. Conceptual problems translate into operational problems, limiting the comparability of instruments and results. In this paper I systematize the fragmented approaches to framing in political communication and integrate them into a comprehensive model. I classify previous approaches to framing research along two dimensions: the type of frame examined (media frames vs. audience frames) and the way frames are operationalized (independent variable or dependent variable). I develop a process model of framing, identifying four key processes that should be addressed in future research: frame building, frame setting, individual-level processes of framing, and a feedback loop from audiences to journalists.     

Expression and distribution of leptospiral outer membrane components during renal infection of hamsters

The outer membrane of pathogenic Leptospira species grown in culture media contains lipopolysaccharide (LPS), a porin (OmpL1), and several lipoproteins, including LipL36 and LipL41. The purpose of this study was to characterize the expression and distribution of these outer membrane antigens during renal infection. Hamsters were challenged with host-derived Leptospira kirschneri to generate sera which contained antibodies to antigens expressed in vivo. Immunoblotting performed with sera from animals challenged with these host-derived organisms demonstrated reactivity with OmpL1, LipL41, and several other proteins but not with LipL36. Although LipL36 is a prominent outer membrane antigen of cultivated L. kirschneri, its expression also could not be detected in infected hamster kidney tissue by immunohistochemistry, indicating that expression of this protein is down-regulated in vivo. In contrast, LPS, OmpL1, and LipL41 were demonstrated on organisms colonizing the lumen of proximal convoluted renal tubules at both 10 and 28 days postinfection. Tubular epithelial cells around the luminal colonies had fine granular cytoplasmic LPS. When the cellular inflammatory response was present in the renal interstitium at 28 days postinfection, LPS and OmpL1 were also detectable within interstitial phagocytes. These data establish that outer membrane components expressed during infection have roles in the induction and persistence of leptospiral interstitial nephritis.     

No evidence for an ischemic penumbra in massive experimental intracerebral hemorrhage

OBJECTIVES: To determine the effect of massive intracerebral hemorrhage (ICH) on regional cerebral blood flow (rCBF) and metabolism, and to test the hypothesis that there is persistent ischemia in the perihematoma region after ICH. BACKGROUND: Cerebral ischemia is postulated to be one of the mechanisms of neural injury after ICH. Presumably the hematoma induces ischemia by mechanical compression of the surrounding microvasculature. METHODS: The authors induced ICH in eight anesthetized mongrel dogs by autologous blood injection (7.5 mL) under arterial pressure in the deep white matter adjacent to the left basal ganglia. They measured serial rCBF using radiolabeled microspheres in regions around and distant to the hematoma, as well as cerebral oxygen extraction, oxygen consumption (CMRO2), glucose utilization, and lactate production by serial sampling of cerebral venous blood from the sagittal sinus. Mean arterial pressure (MAP) and intracranial pressure (ICP) were monitored continuously. All measurements were recorded at 0.5, 1.0, 2.0, 3.5, and 5.0 hours after induction of ICH and compared with prehematoma values. Evans Blue dye was injected at the end of the experiment, and intensity of staining was compared with three control animals. RESULTS: Compared with prehematoma ICP (12.5+/-2.0 mm Hg, mean+/-standard error), significant elevation in ICP was observed after ICH peaking at 5 hours (34.4+/-5.2 mm Hg). Compared with prehematoma MAP (125.8+/-7.0 mm Hg), significant elevation in MAP was observed at 120 minutes after onset of hematoma (139.1+/-4.6 mm Hg), with return to the prehematoma value by 5 hours. There were no significant changes observed in cerebral oxygen extraction (51.4+/-4.3% versus 44.8+/-4.9%) and CMRO2 (1.8+/-0.3 versus 1.64+/-0.2 mL O2/100 g/min) at 5 hours posthematoma (or any other posthematoma measurement) compared with prehematoma values. There were no significant differences observed in rCBF in the perihematoma gray (18.2+/-0.9 mL/100 g/min versus 20.1+/-1.5 mL/100 g/min) or white matter (15.6+/-1.4 mL/100 g/min versus 15.3+/-1.1 mL/100 g/min) at 5 hours posthematoma (or any other posthematoma measurement) compared with prehematoma values. No changes were observed in cerebral glucose utilization, lactate production, and rCBF in other regions after introduction of ICH. Permeability of the blood-brain barrier was more prominent in the ipsilateral hemisphere in animals with ICH compared with control animals. CONCLUSIONS: Despite a prominent increase in ICP and MAP after ICH, the authors found no evidence to support the presence of an ischemic penumbra in the first 5 hours after ICH. Thus, other mechanisms for acute neural injury and late rCBF changes after ICH must be investigated.     

Technique for repair of Descemet membrane detachment

Tuberculous infection of the esophagus is a rare disease and usually occurs secondary to tuberculous mediastinal lymphadenopathy. We report a 74-year-old woman presenting with dysphagia and weight loss. The chest radiograph showed punctuated calcifications lining from the right hilar region to the paracardiac region. Upper gastrointestinal endoscopy revealed a 0.5 x 5 cm lesion localized in the 25th cm of the esophagus covered partly with normal mucosa, partly demonstrating ulcerous areas. Biopsy revealed granulomatous infiltrates being tuberculoid in type. Thorax CT showed a calcified lymph node at the right hilum. The patient did not give consent to therapy and died 1 month later.     

Recent developments in two-pack water-based epoxy coatings

In recent years new curing agent technology has been developed which allows water-based curing agents to be introduced into high performance coating, these are classified according to the type of epoxy resin used. Type I utilises low molecular weight, liquid epoxy resins and Type II pre-formed dispersions of higher molecular weight solid epoxy resins. The chemical composition of the binder of water-borne epoxy coatings plays a critical role in their performance properties, hence some of the structural properties of the amine hardeners will be reviewed. New curing agents will be discussed which demonstrate the versatility these products can offer to the coating formulator. Performance data of clear coats and anti-corrosive primers confirm the applicability of the new systems for the long term protection of steel and concrete surfaces.