Brain MRI and proton MRS findings in infants and children with respiratory chain defects

OBJECTIVE

The aim of this study is to describe neuroimaging patterns in children with respiratory chain (RC) defects using magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (MRS) and to assess their role in the diagnostic evaluation.

METHOD

Neuroimaging studies of 49 children (newborn to 15 years old) with biochemical evidence of RC defect were reviewed. Patients were divided in 3 groups ("definite" = 24, "probable" = 14, "possible" = 11) according to Modified Adult Criteria for the diagnosis of RC defect. Eighty-one MRI studies were reviewed for deep gray and white matter changes, degree of myelination, cerebral and cerebellar atrophy, and 67 proton MRS studies were assessed for the presence or absence of lactate elevation, as well as NAA/Cr ratio. The findings were compared among the 3 groups with chi-square test.

RESULTS

All patients with "pure" myopathy had normal imaging studies. In patients with CNS involvement, significant differences in the frequency of imaging abnormalities among groups were found for deep gray matter (43 %/8 %/0 %; p = 0.01) and for the presence of lactate elevation on proton MRS (81 %/31 %/0 %; p = 0.001).

CONCLUSION

Brain MRI and proton MRS abnormalities were observed only in association with clinical CNS involvement. Deep gray matter signal abnormalities on structural imaging and lactate elevation on proton MRS were more frequently observed in the "definite" group and represent neuroimaging markers for RC mitochondriopathy.

Accuracy of the funnel technique of thoracic pedicle screws insertion in scoliosis surgery--an evaluation by CT-scans

Pedicle screw system has increasingly been used for correction of thoracic scoliosis. It offers several biomechanical advantages over hook system as it controls all three-column of the spine with enhanced stability. Of many techniques of pedicle screw placement in the thoracic spine, the funnel technique has been used in Sarawak General Hospital since 2002. This prospective study aims to assess the accuracy of the placement of thoracic pedicle screws using the funnel technique in the corrective surgery of idiopathic scoliosis. A total of 88 thoracic pedicle screws were inserted into the T4 to T12 vertebrae of 11 patients. Post-operative CT-scan was performed to evaluate the position of the pedicle screw. Seventy six (86.4%) screws were noted to be totally within the pedicle. There was no screw with medial violation of the pedicle, 8 (9.1%) screws breeching the lateral wall of the pedicle and 4 (4.5%) screws with anterior and lateral penetration of the vertebral body. No clinical sequel with the mal-positioned screws was noted. In conclusion, the funnel technique enabled simple, accurate and reliable insertion of pedicle screw even in the scoliotic thoracic spine without the need of any imaging guidance. It is however imperative for the surgeon to have a thorough knowledge of the thoracic spine anatomy, and to be familiar with the technique to insert these screws diligently.

A murine model for the study of immune memory in response to pneumococcal conjugate vaccination

We developed a murine model for assessment of immunological memory and antibody-induced protection to nasopharyngeal (NP) challenges. BALB/c female mice (n = 10 mice per study parameter) were immunized with two priming doses of the licensed 7-valent pneumococcal (Pnc) conjugate vaccine and immune responses [antibody immunoglobulin G (IgG) levels, avidity and opsonophagocytic activity] were monitored for 26 weeks until IgG levels decreased to nearly baseline. A booster dose of either 2 microg conjugate or 5 microg polysaccharide vaccine was given at week 26. The ability of these two treatments to recall immune memory established by the conjugate vaccine was determined for types 4 and 14 for up to 63 days post-booster. The ability of challenge with pneumococcal type 14 to recall the immune response was also evaluated, as well as, the number of antibody secreting cells (ASC) specific to polysaccharide (Ps) 4, 6B, and 14. A higher dose of conjugate vaccine (2 microg) was necessary to elicit a significant increase in IgG levels after priming with one dose. Priming with lower doses (0.5 and 1.0 microg) only elicited modest increases in IgG levels. Recall of the immune response was found with either conjugate or Ps vaccines. NP challenge with type 14 at week 26 did not recall the immune response, although reduction in NP Pnc load was seen post-primary immunization at 5, 10 and 26 weeks. ASCs were detected in response to either conjugate or Ps booster doses. This model allows for the screening and determination of potential alternative vaccination regimens and the study of immunological markers of memory following Pnc vaccination.

Does the discharge ECG provide additional prognostic insight(s) in non-ST elevation ACS patients from that acquired on admission?

BACKGROUND

Although the prognostic value of admission ST changes in patients with non-ST elevation acute coronary syndrome (ACS) is established, the utility of the discharge ECG is unknown. Accordingly, using the PARAGON-B Troponin substudy, we assessed the prevalence of ST depression on both admission and discharge ECG, the likelihood of developing new Q-waves at discharge and the additional prognostic value of these changes.

METHODS AND RESULTS

Nine hundred and eighteen patients were studied; 542 patients (59%) had admission ST downward arrow > or =1mm and 376 patients (41%) did not and their 6-month mortality was 4.4 vs 0.8%, P=0.002, respectively. Of patients with ST downward arrow on admission, 320 (59%) normalized their ST segment at discharge. Of patients without ST downward arrow on admission, 35 (9.3%) developed new ST downward arrow at discharge. Patients with persistent ST downward arrow on discharge had a higher 6-month mortality (6.0 vs 0.9%), (re)MI (16.3 vs 7.4%), and death/(re)MI (20.0 vs 8.3%) than those who never had ST downward arrow (all P< or =0.002). Two hundred and fifty-six patients had Q-waves on admission whereas by discharge 320 had Q-waves. Patients with Q-waves on discharge vs those without had a higher mortality (4.8 vs 1.9%), (re)MI (13.8 vs 8.3%), and death/(re)MI (16.4 vs 9.6%) at 6 months (all P< or =0.021).

CONCLUSIONS

This study highlights that the dynamic ECG changes which occur between admission and discharge in non-ST elevation ACS patients allows further risk stratification in determining the likelihood of 6-month death and/or re(MI).

Affinity purification of diverse plant and human 14-3-3-binding partners

Many proteins that bind to a 14-3-3 column in competition with a 14-3-3-binding phosphopeptide have been purified from plant and mammalian cells and tissues. New 14-3-3 targets include enzymes of biosynthetic metabolism, vesicle trafficking, cell signalling and chromatin function. These findings indicate central regulatory roles for 14-3-3s in partitioning carbon among the pathways of sugar, amino acid, nucleotide and protein biosynthesis in plants. Our results also suggest that the current perception that 14-3-3s bind predominantly to signalling proteins in mammalian cells is incorrect, and has probably arisen because of the intensity of research on mammalian signalling and for technical reasons.

Facial trauma and ocular/orbital injury

BACKGROUND AND OBJECTIVES

Ocular injuries occur commonly in patients with facial trauma. Patients with significant eye injuries may present with grossly normal eyes and good visual acuity; however, subsequent ocular disorders may become apparent. The estimates of incidence vary considerably. Trauma is the second leading cause of blindness, and a review is, therefore, warranted.

METHODS AND MATERIALS

Several extensive studies are reviewed. Blunt and penetrating trauma are examined by their respective subdivisions. The initial assessment and ophthalmologic examination of patients with facial trauma are discussed, and the type of injury that may occur secondary to trauma is delineated. Management is reviewed and discussed, including a recently developed diagnostic scoring system. Three clinical cases illustrate the procedure.

RESULTS AND/OR CONCLUSIONS

The diagnosis of ocular injuries resulting from trauma is difficult. The recently introduced scoring system was found to improve the procedure. Based on this system, the authors have devised an algorithm to assist the clinician, with emphasis on visual acuity and the importance of visual examination.

11 Beta-hydroxysteroid dehydrogenase type 1 is induced in human monocytes upon differentiation to macrophages

11beta-hydroxysteroid dehydrogenases (11beta-HSD) perform prereceptor metabolism of glucocorticoids through interconversion of the active glucocorticoid, cortisol, with inactive cortisone. Although the immunosuppressive and anti-inflammatory activities of glucocorticoids are well documented, the expression of 11beta-HSD enzymes in immune cells is not well understood. Here we demonstrate that 11beta-HSD1, which converts cortisone to cortisol, is expressed only upon differentiation of human monocytes to macrophages. 11beta-HSD1 expression is concomitant with the emergence of peroxisome proliferator activating receptor gamma, which was used as a surrogate marker of monocyte differentiation. The type 2 enzyme, 11beta-HSD2, which converts cortisol to cortisone, was not detectable in either monocytes or cultured macrophages. Incubation of monocytes with IL-4 or IL-13 induced 11beta-HSD1 activity by up to 10-fold. IFN-gamma, a known functional antagonist of IL-4 and IL-13, suppressed the induction of 11beta-HSD1 by these cytokines. THP-1 cells, a human macrophage-like cell line, expressed 11beta-HSD1 and low levels of 11beta-HSD2. The expression of 11beta-HSD1 in these cells is up-regulated 4-fold by LPS. In summary, we have shown strong expression of 11beta-HSD1 in cultured human macrophages and THP-1 cells. The presence of the enzyme in these cells suggests that it may play a role in regulating the immune function of these cells.

Statins suppress THP-1 cell migration and secretion of matrix metalloproteinase 9 by inhibiting geranylgeranylation

Macrophages secrete matrix metalloproteinase 9 (MMP-9), an enzyme that weakens the fibrous cap of atherosclerotic plaques, predisposing them to plaque rupture and subsequent ischemic events. Recent work indicates that statins strongly reduce the possibility of heart attack. Furthermore, these compounds appear to exert beneficial effects not only by lowering plasma low-density-lipoprotein cholesterol but also by directly affecting the artery wall. To evaluate whether statins influence the proinflammatory responses of monocytic cells, we studied their effects on the chemotactic migration and MMP-9 secretion of human monocytic cell line THP-1. Simvastatin dose dependently inhibited THP-1 cell migration mediated by monocyte chemoattractant protein 1, with a 50% inhibitory concentration of about 50 nM. It also inhibited bacterial lipopolysaccharide-stimulated secretion of MMP-9. The effects of simvastatin were completely reversed by mevalonate and its derivatives, farnesylpyrophosphate and geranylgeranyl pyrophosphate, but not by ubiquinone. Additional studies revealed similar but more profound inhibitory effects with L-839,867, a specific inhibitor of geranylgeranyl transferase. However, alpha-hydroxyfarnesyl phosphonic acid, an inhibitor of farnesyl transferase, had no effect. C3 exoenzyme, a specific inhibitor of the prenylated small signaling Rho proteins, mimicked the inhibitory effects of simvastatin and L-839,867. These data supported the role of geranylgeranylation in the migration and MMP-9 secretion of monocytes.

Body-image attitudes and psychosocial functioning in Euro-American and Asian-American college women

Euro-American (n = 94) and Asian-American (n = 72) college women were compared on multiple dimensions of body image, including global body satisfaction, preoccupation with appearance, satisfaction with individual body parts or features, and weight concern, and psychosocial functioning, including self-esteem, public self-consciousness, social anxiety, and public body consciousness. Both groups reported similar scores on these variables and showed similar patterns of correlations between body-image and psychosocial variables. Despite similar global body satisfaction, there were group differences in satisfaction with individual body parts or features, with Asian-American women reporting lower satisfaction with six parts or features and higher satisfaction with one feature. Stepwise multiple regression analyses predicting global body satisfaction from individual body parts or features suggested that both the specific body parts or features most salient to global body satisfaction and the relative influence of these parts or features varied as a function of ethnicity. Implications of these findings for research and practice are discussed.

Induction of 11beta-hydroxysteroid dehydrogenase type 1 but not -2 in human aortic smooth muscle cells by inflammatory stimuli

The 11beta-hydroxysteroid dehydrogenase (11beta-HSD) enzymes catalyze the interconversion of active glucocorticoids (GC) with their inert metabolites, thereby regulating the functional activity of GC. While 11beta-HSD type 1 (11beta-HSD1) activates GC from their 11-keto metabolites, 11beta-HSD type 2 (11beta-HSD2) inactivates GC. Here we report that both of these enzymes are expressed in human aortic smooth muscle cells (SMC), and that 11beta-HSD1 is more abundant and is differentially regulated relative to 11beta-HSD2. Stimulation of SMC with IL-1beta or TNFalpha led to a time- and dose-dependent increase of mRNA levels for 11beta-HSD1, while 11beta-HSD2 mRNA levels decreased. Parallel enzyme activity studies showed increased conversion of 3H-cortisone to 3H-cortisol but not 3H-cortisol to 3H-cortisone, demonstrating 11beta-HSD1 in SMC acts primarily as a reductase. A similar increase of 11beta-HSD1 mRNA expression was also found in human bronchial SMC upon stimulation, indicating the regulatory effect is not limited to vascular smooth muscle. Additional parallel studies revealed a similar pattern of induction for 11beta-HSD1 and monocyte chemoattractant protein-1, a well-defined proinflammatory molecule. These data suggest 11beta-HSD1 may play an important role in regulating inflammatory responses in the artery wall and lung.

Lipids, apoprotein B, and associated coronary risk factors in urban and rural older Mexican populations

The objective of this comparative cross-sectional study was to determine the prevalence of dyslipidemias and examine its association with food intake and metabolic variables in urban and rural elder Mexican populations. Three different communities (urban areas of medium and low income and a rural area) were studied. A total of 344 subjects aged 60 years and older and 273 aged 35 to 59 years were included. The evaluated parameters were personal medical data, 24-hour diet recall, and fasting plasma lipids, insulin, and glucose levels. Older subjects, especially men, living in the rural area had lower cholesterol levels (5.02 +/- 0.97 v 5.6 +/- 1.07 mmol/L; P <.05) and insulin levels (12 +/- 10 v 42 +/- 68 mU/mL) and higher high-density lipoprotein cholesterol concentrations (1.31 +/- 0.36 v 1.07 +/-0.28 mmol/L) than the elders from the urban medium-income group. Possible explanations for these differences are found in the dietary habits of the groups. Rural elders had higher amounts of fiber (20 +/- 11 v 10 +/- 6 g/d) and carbohydrate (70% +/- 0.08% v 52% +/- 0.11% of calories) and lower fat (18% +/- 0.07% v 33% +/- 0.1% of calories) in their diets. In the urban groups, low-density lipoprotein hypercholesterolemia was present in 17.8% of adult and 39.1% of elderly women (P =.00001). In conclusion, environmental factors still play a prominent role in the pathophysiology of the dyslipidemias in the elderly.

Irreversible brain creatine deficiency with elevated serum and urine creatine: a creatine transporter defect?

Recent reports highlight the utility of in vivo magnetic resonance spectroscopy (MRS) techniques to recognize creatine deficiency syndromes affecting the central nervous system (CNS). Reported cases demonstrate partial reversibility of neurologic symptoms upon restoration of CNS creatine levels with the administration of oral creatine. We describe a patient with a brain creatine deficiency syndrome detected by proton MRS that differs from published reports. Metabolic screening revealed elevated creatine in the serum and urine, with normal levels of guanidino acetic acid. Unlike the case with other reported creatine deficiency syndromes, treatment with oral creatine monohydrate demonstrated no observable increase in brain creatine with proton MRS and no improvement in clinical symptoms. In this study, we report a novel brain creatine deficiency syndrome most likely representing a creatine transporter defect.

Prevalence and penetrance of germline BRCA1 and BRCA2 mutations in a population series of 649 women with ovarian cancer

A population-based series of 649 unselected incident cases of ovarian cancer diagnosed in Ontario, Canada, during 1995-96 was screened for germline mutations in BRCA1 and BRCA2. We specifically tested for 11 of the most commonly reported mutations in the two genes. Then, cases were assessed with the protein-truncation test (PTT) for exon 11 of BRCA1, with denaturing gradient gel electrophoresis for the remainder of BRCA1, and with PTT for exons 10 and 11 of BRCA2. No mutations were found in all 134 women with tumors of borderline histology. Among the 515 women with invasive cancers, we identified 60 mutations, 39 in BRCA1 and 21 in BRCA2. The total mutation frequency among women with invasive cancers, 11.7% (95% confidence interval [95%CI] 9.2%-14.8%), is higher than previous estimates. Hereditary ovarian cancers diagnosed at age <50 years were mostly (83%) due to BRCA1, whereas the majority (60%) of those diagnosed at age >60 years were due to BRCA2. Mutations were found in 19% of women reporting first-degree relatives with breast or ovarian cancer and in 6.5% of women with no affected first-degree relatives. Risks of ovarian, breast, and stomach cancers and leukemias/lymphomas were increased nine-, five-, six- and threefold, respectively, among first-degree relatives of cases carrying BRCA1 mutations, compared with relatives of noncarriers, and risk of colorectal cancer was increased threefold for relatives of cases carrying BRCA2 mutations. For carriers of BRCA1 mutations, the estimated penetrance by age 80 years was 36% for ovarian cancer and 68% for breast cancer. In breast-cancer risk for first-degree relatives, there was a strong trend according to mutation location along the coding sequence of BRCA1, with little evidence of increased risk for mutations in the 5' fifth, but 8.8-fold increased risk for mutations in the 3' fifth (95%CI 3.6-22.0), corresponding to a carrier penetrance of essentially 100%. Ovarian, colorectal, stomach, pancreatic, and prostate cancer occurred among first-degree relatives of carriers of BRCA2 mutations only when mutations were in the ovarian cancer-cluster region (OCCR) of exon 11, whereas an excess of breast cancer was seen when mutations were outside the OCCR. For cancers of all sites combined, the estimated penetrance of BRCA2 mutations was greater for males than for females, 53% versus 38%. Past studies may have underestimated the contribution of BRCA2 to ovarian cancer, because mutations in this gene cause predominantly late-onset cancer, and previous work has focused more on early-onset disease. If confirmed in future studies, the trend in breast-cancer penetrance, according to mutation location along the BRCA1 coding sequence, may have significant impact on treatment decisions for carriers of BRCA1-mutations. As well, BRCA2 mutations may prove to be a greater cause of cancer in male carriers than previously has been thought.

TBX5 transcription factor regulates cell proliferation during cardiogenesis

Mutations in human TBX5, a member of the T-box transcription factor gene family, cause congenital cardiac septation defects and isomerism in autosomal dominant Holt-Oram syndrome. To determine the cellular function of TBX5 in cardiogenesis, we overexpressed wild-type and mutant human TBX5 isoforms in vitro and in vivo. TBX5 inhibited cell proliferation of D17 canine osteosarcoma cells and MEQC quail cardiomyocyte-like cells in vitro. Mutagenesis of the 5' end of the T-box but not the 3' end of the T-box abolished this effect. Overexpression of TBX5 in embryonic chick hearts showed that TBX5 inhibits myocardial growth and trabeculation. TBX5 effects in vivo were abolished by Gly80Arg missense mutation of the 5' end of the T-box. PCNA analysis in transgenic chick hearts revealed that TBX5 overexpression does suppress embryonic cardiomyocyte proliferation in vivo. Inhibitory effects of TBX5 on cardiomyocyte proliferation include a noncell autonomous process in vitro and in vivo. TBX5 inhibited proliferation of both nontransgenic cells cocultured with transgenic cells in vitro and nontransgenic cardiomyocytes in transgenic chick hearts with mosaic expression of TBX5 in vivo. Immunohistochemical studies of human embryonic tissues, including hearts, also demonstrated that TBX5 expression is inversely related to cellular proliferation. We propose that TBX5 can act as a cellular arrest signal during vertebrate cardiogenesis and thereby participate in modulation of cardiac growth and development.

Production of matrix metalloproteinase-9 in CaCO-2 cells in response to inflammatory stimuli

Matrix metalloproteinase-9 (MMP-9) may play an important role in the development of inflammatory bowel disease (IBD). However, the cellular source of MMP-9 in the inflamed mucosa of IBD remains unclear. Here we report that MMP-9 mRNA is expressed in CaCO-2 cells, an intestinal epithelial cell line, and that its expression is upregulated by inflammatory stimuli. Stimulation of CaCO-2 cells with interleukin-1beta (IL-1beta) or tumor necrosis factor-alpha (TNF-alpha) led to a dose-dependent increase in expression and secretion of MMP-9. In contrast, bacterial lipopolysaccharide (LPS) failed to induce expression or secretion of MMP-9, suggesting that an inflammatory reaction leading to cytokine release is a necessary step for the induction of MMP-9 release in intestinal epithelial cells. Additional studies show that induction of MMP-9 mRNA peaked at 16 h of IL-1beta stimulation, whereas expression of monocyte chemoattractant protein-1 (MCP-1) and IL-8 both peaked at 3 h of stimulation. Treatment of CaCO-2 cells with rosiglitazone, a peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonist, significantly reduced secretion of MMP-9, indicating that agents that activate PPAR-gamma may have therapeutic use in patients with IBD.