Organic Rice Production Practices: Effects on Grain End-Use Quality, Healthfulness, and Safety

Demand for rice labeled as organic is growing globally. Consumers state that foods labeled as organic are nutritionally superior and safer than their conventionally produced equivalent. The research question for this systematic review is as follows: is there a difference between the effects of sustainable agriculture and conventional farming methods on rice grain end-use quality, healthfulness, and safety? The studies (n = 23) examined for this review suggest that organic production practices don't influence most end-use quality (e.g., chalk, milling yield, pasting properties) and healthfulness (e.g., gamma-oryzanol fraction and tocols) traits studied, or if it does, it will be to a small degree. If differences in end-use quality traits are found, they will be associated with grain protein content, which varies along with the dose of nitrogen applied during rice growth. We conclude that the studies evaluated in this review found that organically produced rice grain was less likely to contain residues of the pesticides (e.g., organochlorine) examined in the study than the rice is grown using conventional methods. There was some evidence that organically grown rice is more likely to be contaminated with mycotoxin-producing fungi and some mycotoxins. Common shortcomings of the studies were that they were poorly designed, with limited to no details of the cultural management practices used to grow the rice studied, the length of time fields was under organic management not stated, cultivars were not named, and the data wasn't analyzed statistically.

High Resistant Starch Rice: Variation in Starch Related SNPs, and Functional, and Sensory Properties

Human diets containing greater resistant starch (RS) are associated with superior glycemic control. Although high amylose rice has higher RS (29 g/kg to 44 g/kg) than lower amylose content varieties, sensory and processing properties associated with RS have not been evaluated. This study used variants of Waxy and starch synthase II a (SSIIa) genes to divide high amylose (256 g/kg to 284 g/kg) varieties into three haplotypes to examine their effects on RS, RVA parameters, and 14 cooked rice texture properties. RVA characteristics were influenced by both genes with peak and hotpaste viscosity differentiating the three haplotypes. Setback from hotpaste viscosity was the only RVA parameter correlated with RS content across three haplotypes (r = −0.76 to −0.93). Cooked rice texture attributes were impacted more by Waxy than by SSIIa with initial starch coating, roughness, and intact particles differentiating the three haplotypes. Pairwise correlation (r = 0.46) and PCA analyses suggested that roughness was the only texture attribute associated with RS content; while protein content influenced roughness (r = 0.49) and stickiness between grains (r = 0.45). In conclusion, variation exists among genetic haplotypes with high RS for sensory traits that will appeal to diverse consumers across the globe with limited concern for negatively affecting grain processing quality.

Menu Engineering and Dietary Behavior Impact on Young Adults' Kilocalorie Choice

The obesity pandemic is associated with increased consumption of restaurant food. Labeling of menus is an intervention used to provide consumers with kilocalorie (calorie) information in hopes of them making healthier food choices. This study evaluated the relationship between young adults' calorie choices on restaurant menus and menu design, dietary behaviors, and demographic characteristics. A 3 (fast-casual restaurants) × 4 (menu-designs based on menu engineering theories) between-subjects (n = 480, 18-24-year olds) experimental design was used. The relationship between the participants' calorie choices (high versus low) and menu design, stage of change, gender, race, educational level and weight status was evaluated using logistic regression. All independent variables had at least one category that had greater odds (CI 95% ± 5%) of subjects choosing a lower calorie entree, except education level and race/ethnic group. Normal weight and overweight subjects had greater odds of choosing lower calorie entrees than those that were obese. In addition, subjects that had started to control their calorie intake for less than six months or had sustained this change for at least six months, had greater odds of choosing lower calorie entrees compared to others. Including a green symbol and calories on fast casual restaurant menus may influence some young adults to choose lower calorie entrees.

The potential of rice to offer solutions for malnutrition and chronic diseases

It is internationally accepted that malnutrition and chronic diseases in developing countries are key limitations to achieving the Millennium Development Goals. In many developing countries, rice is the primary source of nutrition. In those countries, the major forms of malnutrition are Fe-induced anaemia, Zn deficiency and Vitamin A deficiency, whereas the major chronic disease challenges are Type II diabetes, cardiovascular disease and some cancers. There is a growing corpus of evidence regarding both limitations and opportunities as to how rice could be an effective vehicle by which to tackle key nutrition and health related problems in countries with limited resources. Rice breeding programs are able to focus on developing new varieties carrying enhanced amounts of either Fe, Zn or beta-carotene because of large public investment, and the intuitive link between providing a mineral/vitamin to cure a deficiency in that mineral/vitamin. By contrast, there has been little investment in progressing the development of particular varieties for potential impact on chronic diseases. In this review article we focus on the broad battery of evidence linking rice-related nutritional limitations to their impact on a variety of human health issues. We discuss how rice might offer sometimes even simple solutions to rectifying key problems through targeted biofortification strategies and finally, we draw attention to how recent technological (-omics) developments may facilitate untold new opportunities for more rapidly generating improved rice varieties specifically designed to meet the current and future nutritional needs of a rapidly expanding global population.

What is next for the Dietary Reference Intakes for bone metabolism related nutrients beyond calcium: phosphorus, magnesium, vitamin D, and fluoride?

The science supporting the Dietary Reference Intakes (DRI) for phosphorus, magnesium, vitamin D, and fluoride was examined in this review. Along with the previous article on calcium in this series both of these reviews represent all the DRI for nutrients considered essential for bone metabolism and health, as reported in the Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride (Institute of Medicine, Food and Nutrition Board (FNB), 1997). The Recomended Dietary Allowances (RDA) or adequate intake (AI), and the tolerable upper intake level (UL) were recommended for each of these essential nutrients. For adults and in the case of fluoride, for infants as well, UL were calculated since all of these nutrients have the potential for mild to detrimental side effects. Dietary intake data and controversies regarding the role these nutrients may play in other chronic diseases have also been discussed. Advances and controversies reported since the publication of the DRI for these nutrients were also addressed in this review. A recent Dietary Reference Intake Research Synthesis Workshop report identified an extensive range of suggested future research directions needed to improve our understanding of these bone-related nutrients and their contributions to human health.

Review of the dietary reference intake for calcium: where do we go from here?

In this article the science relied on to establish the Dietary Reference Intakes (DRI) specifically for calcium was examined. The latest dietary recommendations for the essential nutrients significant with respect to their roles in bone metabolism and health were reported in the Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride (1997) (NIM, 1997). For calcium an adequate intake was recommended because insufficient data were available at the time to determine specific Recommended Dietary Allowances. Dietary intake data and the controversies regarding the role calcium may play in other chronic diseases have also been discussed. Advances and continued dilemmas regarding these topics reported since the publication of the DRI were also addressed in this review. A recent Dietary Reference Intake Research Synthesis Workshop report identified an extensive range of suggested future research directions needed to improve our understanding of calcium and bone and health.

QTL mapping of grain quality traits from the interspecific cross Oryza sativa x O. glaberrima

International rice export markets are increasing demands for rapid improvements in grain quality characteristics. The African rice Oryza glaberrima is a new potential source of genes that will enhance the eating, cooking, and milling properties of the rice grain. The objective of this research was to identify and characterize quantitative trait loci (QTLs) among 312 doubled haploid lines derived from the BC3F1 of an interspecific cross of O. sativa x O. glaberrima. Genetic material was planted in replicated plots and evaluated for ten grain quality traits in 2001 in Colombia. A linkage map was constructed with 100 polymorphic microsatellite markers using the mapdisto software program to adjust for segregation distortion. Transgressive segregation was observed for all traits. Interval and composite interval analyses identified 27 QTLs for nine characters located on 11/12 chromosomes. The chromosomal positions of QTLs for percentage amylose, alkali-spreading score, and percentage protein were in agreement with data reported by others, whereas QTL markers for percentage head rice, percentage milled rice, percentage protein, and percentage brown rice were different in our mapping population. Five major QTLs were found to be associated with improved percentage rice bran, percentage amylose, and alkali-spreading score. Seven QTLs for improved percentage rice bran, percentage milled rice, alkali-spreading score, percentage protein, and grain length/width ratio were derived from the O. glaberrima accession. Three new QTLs for percentage rice bran are reported here for the first time. Results from this study suggest that the African rice might be a valuable new source for introgression and improvement of several traits that affect quality traits demanded by the different rice export markets.

Screening for 2-acetyl-1-pyrroline in the headspace of rice using SPME/GC-MS

Solid phase microextraction (SPME) is used to collect and concentrate the compounds in the headspace of rice. This research describes optimization parameters of temperature, moisture, and sampling time. Optimization was based upon the recovered levels of 2-acetyl-1-pyrroline (2-AP), the popcorn aroma in aromatic rice. The method uses a sampling temperature of 80 degrees C and adds 100 microL of water to a 0.75 g sample of rice. The rice was preheated for 25 min, a carboxen/DVB/PDMS SPME fiber was exposed to the headspace for 15 min, and a subsequent GC-MS analysis took 35 min. Samples of rice can be analyzed as the flour, milled kernels, or brown rice. Twenty-one experimental rice varieties were analyzed by the SPME method and compared to a wet technique. Recoveries of several nanograms of 2-AP from 0.75 g samples of aromatic rice were observed, whereas only trace amounts of 2-AP were recovered from nonaromatic rice. Recovery from a single SPME headspace analysis is calculated to be 0.3% of the total 2-AP in the sample.

Evidence for stabilizing selection in a eukaryotic enhancer element

Eukaryotic gene expression is mediated by compact cis-regulatory modules, or enhancers, which are bound by specific sets of transcription factors. The combinatorial interaction of these bound transcription factors determines time- and tissue-specific gene activation or repression. The even-skipped stripe 2 element controls the expression of the second transverse stripe of even-skipped messenger RNA in Drosophila melanogaster embryos, and is one of the best characterized eukaryotic enhancers. Although even-skipped stripe 2 expression is strongly conserved in Drosophila, the stripe 2 element itself has undergone considerable evolutionary change in its binding-site sequences and the spacing between them. We have investigated this apparent contradiction, and here we show that two chimaeric enhancers, constructed by swapping the 5' and 3' halves of the native stripe 2 elements of two species, no longer drive expression of a reporter gene in the wildtype pattern. Sequence differences between species have functional consequences, therefore, but they are masked by other co-evolved differences. On the basis of these results, we present a model for the evolution of eukaryotic regulatory sequences.

Surgery for gynecologic malignancies

Surgery continues to play a primary role in the investigation and treatment of gynecologic neoplasia. Cold-knife conization is still preferable for diagnosis and treatment of more problematic preinvasive cervical lesions. Newer reconstructive techniques can improve quality of life in exenteration patients. Efforts continue to reduce morbidity associated with vulvar surgery and groin node dissection. Accurate staging and maximum cytoreduction remain essential goals in primary surgery for ovarian cancers. The utility of secondary surgery for disease assessment or further treatment is controversial. Laparoscopy at present has a limited role in gynecologic oncology but may be useful for prophylactic oophorectomy in selected individuals.

Control of NMDA receptor activation by a glycine transporter co-expressed in Xenopus oocytes

We present evidence that membrane transporters can control the membrane receptor's agonist concentration in restricted extracellular spaces of a biological model. The model is constructed by co-expressing glycine/Na/Cl cotransporters (GLYT1b) and NMDA receptors (NMDARs) (composed of the subunits NR1 and NR2A or NR2B) in Xenopus oocytes. We use the high-affinity glycine site of the NMDARs as a sensor of the actual juxtamembrane glycine concentration. We show that glycine uptake by GLYT1b dramatically reduces NMDAR currents by reducing the glycine concentration in extracellular spaces in which diffusion is restricted. This effect appears only in oocytes in which GLYT1b and NMDAR are co-expressed. It is Na+- and voltage-dependent, and is abolished when Na+ is replaced by Li+ and when glycine is replaced by D-serine (a coagonist of the NMDAR that is not transported by GLYT1b). These results demonstrate the ability of the GLYT transporter to reduce glycine concentration at the level of NMDARs in restricted diffusion spaces. This observation could account for a prevalent role of membrane transporters in the modulation of synapse transmission in the CNS. From a more general point of view, our results draw attention to possible significant discrepancies between local concentrations at the level of substrate targets in biological membranes and their concentration in the bulk solution when membrane transporters are present.

Superparamagnetic iron oxide--enhanced versus gadolinium-enhanced MR imaging for differential diagnosis of focal liver lesions

PURPOSE

To assess AMI-25- versus gadolinium-enhanced magnetic resonance (MR) imaging in the differential diagnosis of liver tumors.

MATERIALS AND METHODS

Twenty-nine patients with liver tumors underwent unenhanced, AMI-25-enhanced (15 micromol/kg), and gadolinium-enhanced(0.1 mmol/kg) imaging within 2 weeks.

RESULTS

A significant (P< .05) difference in percentage signal intensity loss (PSIL) was seen in benign tumors on AMI-25-enhanced proton-density-weighted images (nine focal nodular hyperplasia [FNH], 41%; one adenoma, 32.4%) versus malignant tumors. Gadolinium-enhanced T1-weighted gradient-echo images showed strong enhancement in benign lesions (seven FNH, 147.5%; one adenoma, 91.3%) and moderate enhancement in malignant tumors (eight hepatocellular carcinomas, 116.2%, 11 metastases, 39.7%). Receiver operating characteristic analysis revealed a threshold PSIL of 10% on AMI-25-enhanced images as the most essential criteria to distinguish benign from malignant lesions (sensitivity, 88%; specificity. 89%). Interobserver analysis for two observers revealed specificity of 93% for AMI-25-enhanced imaging versus 81.5% for gadolinium-enhanced MR imaging.

CONCLUSION

AMI-25 decreased the SI of benign tumors and helped differentiate benign from malignant tumors.

Sjoegren's syndrome: MR imaging of the parotid gland

To date, myoepithelial sialoadenitis (Sjoegren's syndrome) has been diagnosed with sialography and other techniques. First results of MR imaging offer new possibilities in the diagnostic imaging of this disease. Thirty-six patients with immunohistologically and serologically confirmed Sjoegren's syndrome and 25 patients suffering from other diseases, included as a control group, were examined by MR in transverse and coronal orientation. T-2-weighted sequences (TR/TE 1600/25/90) and T1-weighted sequences (TR/TE 500/25 ms) plain and after Gd-DTPA administration were obtained. In all patients the parotid gland showed characteristic internal patterns and abnormalities in gland size. There was a nonhomogeneous internal pattern with a characteristic speckled, honeycomb-like appearance visible especially on T2-weighted sequences. Enhancement with Gd-DTPA yielded no additional information. A staging system with four stages of Sjoegren's syndrome (no characteristic changes to a nodular and swollen gland) was developed. Magnetic resonance has become an important new tool in assessing parotid gland changes in patients suffering from Sjoegren's syndrome, and could well replace the more invasive and unpleasant diagnostic methods in the near future.

cAMP and PMA enhance the effects of IGF-I in the proliferation of endometrial adenocarcinoma cell line HEC-1-A by acting at the G1 phase of the cell cycle

The present study was undertaken to determine whether endometrial cancer cell line HEC-1-A differ from nontransformed cells, in that the cAMP and protein kinase C pathways may enhance IGF-I effects in mitogenesis by acting at the G1 phase of the cell cycle instead of G0. Immunofluorescence staining of HEC-1-A cells using the proliferating cell nuclear antigen (PCNA) monoclonal antibody and flow cytometric analysis determined that HEC-1-A cells do not enter the G0 phase of the cell cycle when incubated in a serum-free medium. Approximately 51% of the cells were in G1, 12% were in S and 37% in G2 phase of the cell cycle prior to treatment. Forskolin and phorbol-12-myristate 13-acetate (PMA) were used to stimulate cAMP production and protein kinase C activity, respectively. IGF-I, forskolin and PMA each increased (P < 0.01) [3H]-thymidine incorporation in a dose and time dependent manner. The interaction of forskolin and PMA with IGF-I was then determined. Cells preincubated with forskolin or PMA followed by incubation with IFG-I incorporated significantly more (P < 0.01) [3H]-thymidine into DNA than controls or any treatment alone. It is concluded that forskolin and, to a lesser extent, PMA exert their effect at the G1 phase of the cycle to enhance IGF-I effects in cell proliferation.

MR diagnosis of head and neck tumors: comparison of contrast enhancement with triple-dose gadodiamide and standard-dose gadopentetate dimeglumine in the same patients

OBJECTIVE

The purpose of this study was to compare the relative values of MR images obtained with a triple dose of gadodiamide and MR images obtained with the standard dose of gadopentetate dimeglumine for the detection and determination of the extent of tumors of the head and neck.

MATERIALS AND METHODS

Forty-two patients with benign and malignant tumors of the head and neck were examined with contrast-enhanced MR imaging in a comparison of a triple dose of gadodiamide (0.3 mmol per kilogram body weight) and a standard dose (0.1 mmol per kilogram body weight) of gadopentetate dimeglumine. All patients underwent MR imaging with both doses of contrast material. Contrast-to-noise ratios and the percentage enhancement of normal and abnormal structures were calculated, and delineation of the lesion and the contrast between tumor and surrounding tissue were evaluated visually.

RESULTS

Statistical analysis (Friedman test and Wilcoxon test) of the contrast-to-noise ratios between tumor and white matter, the percentage enhancement, and the visual assessment rating revealed a statistically significant superiority of the triple dose of gadodiamide over the standard dose of gadopentetate dimeglumine. Tumor/muscle contrast-to-noise ratios were not significantly different with the two doses. The detection rate for tumors was no better with the triple dose of gadodiamide than with the standard dose of gadopentetate dimeglumine.

CONCLUSION

Use of the triple dose of gadodiamide results in a statistically significant improvement in the visual assessment rating, but it does not increase the number of tumors detected on MR images over the number detected with the standard dose of gadopentetate dimeglumine and does not appear to alter the differential diagnosis.

Glomus tumors of the skull base: combined use of MR angiography and spin-echo imaging

PURPOSE

To evaluate the use of magnetic resonance (MR) angiography in the diagnosis of glomus tumors of the skull base.

MATERIALS AND METHODS

In 40 patients with pulsatile tinnitus, spin-echo (SE) images, single sections, and maximum intensity projections from gradient-echo sequences, including arterial MR angiography and MR venography, were evaluated for tumor detection. Interpretations by two independent observers were correlated with findings from histologic examination, digital subtraction angiography, computed tomography, and clinical follow-up.

RESULTS

Glomus tumors were detected near the tympanic plexus (n = 8) and close to the superior (n = 8) and inferior (n = 1) ganglia of the vagus nerve. Sixteen of 18 proved tumors were detected with SE images alone. Although four high-lying jugular bulbs were misinterpreted as tumor due to similar signal intensity, combined evaluation allowed differentiation between tumor and sinusal blood flow in all cases.

CONCLUSION

The authors recommend combined SE imaging and MR angiography for ruling out tumor in patients with pulsatile tinnitus.

Dural sinus thrombosis: value of venous MR angiography for diagnosis and follow-up

OBJECTIVE

The purpose of this study was to determine the value of venous MR angiography as the sole procedure for the diagnosis and follow-up of dural sinus thrombosis.

MATERIALS AND METHODS

Forty-two patients with clinical findings suggestive of dural sinus thrombosis were examined with venous MR angiography and spin-echo MR imaging. Maximum-intensity-projection reconstructions and individual sections of the MR angiograms were examined for direct and indirect signs of dural sinus thrombosis by assessing flow signal from the major sinuses, the jugular bulb, upper jugular veins, ascending cortical veins (occlusion or increased flow due to formation of collaterals), diploe (emissary) veins and extracranial veins, and the deep subcortical veins (Galen's and internal cerebral veins). Direct signs of dural sinus thrombosis on MR angiograms included lack of typical high flow signal from a sinus that did not appear aplastic or hypoplastic on single sections from MR angiography and the frayed appearance of the flow signal from a sinus after recanalization. Indirect signs of dural sinus thrombosis included evidence of formation of collaterals, unusually prominent flow signal from deeper medullary veins, cerebral hemorrhage, visualization of emissary veins, and signs of increased intracranial pressure. When available, conventional angiograms were evaluated by analogous criteria as appropriate. Digital subtraction or cut-film angiograms were available for correlation in nine patients. In nine patients, MR angiography was repeated up to eight times during the course of follow-up. The results of MR angiography for all patients were compared with results in 10 control subjects. Confirmation of the diagnosis of dural sinus thrombosis was based either on conventional angiographic findings or on the changes seen in follow-up examinations.

RESULTS

Dural sinus thrombosis could be ruled out in 25 of the 42 patients on the basis of clinical and MR angiographic findings. In 17 patients with MR angiographic findings that indicated dural sinus thrombosis, conventional angiography confirmed the diagnosis in nine patients, and changes seen on repeat MR angiograms during follow-up confirmed the diagnosis in nine patients as well (one patient's diagnosis was confirmed by both techniques). Individual frames from two-dimensional fast low-angle shot sequences allowed direct visualization of thrombus. Limited spin-echo sequences as performed here provided inconsistent findings and were insufficient for diagnosis. In the 10 control subjects, attenuation of flow signal was seen in the torcular Herophili in all studies; one subject had a nonpathologic variant of the sinojugular system.

CONCLUSION

MR angiography is the technique of choice for diagnostic evaluation and follow-up of dural sinus thrombosis, and it is reliable as the sole examination for this condition. When MR angiographic findings are unremarkable and other abnormalities must be ruled out, routine spin-echo MR imaging should be performed.

An essential role for HLA-DM in antigen presentation by class II major histocompatibility molecules

In antigen-presenting cells, class II molecules of the major histocompatibility complex (MHC) bind peptides derived from endocytosed proteins. In certain B-lymphoblastoid cell mutants, MHC class II molecule-peptide complex formation is impaired, resulting in deficient antigen-presenting function. MHC deletion mutants with this defect map the responsible gene(s) to the class II region of the MHC. Here we report that multiple independent mutants with the class II presentation defect harbour lesions in HLA-DMB, an MHC-linked gene encoding a class II-like beta-chain. Expression of DMB complementary DNA in mutants lacking DMB messenger RNA restores the wild-type phenotype. These results establish HLA-DM as a critical regulatory molecule in class II-restricted antigen presentation and suggest that it functions at an intracellular site to promote class II molecule-peptide association.

Kallman syndrome versus idiopathic hypogonadotropic hypogonadism at MR imaging

PURPOSE

To identify morphologic differences between Kallman syndrome (KS) and idiopathic hypogonadotropic hypogonadism (IHH) and establish a role for magnetic resonance (MR) imaging in these disorders.

MATERIALS AND METHODS

Twenty-eight patients were compared with 10 eugonal male volunteers. Eighteen patients had KS (hypogonadotropic hypogonadism with anosmia) and 10 had IHH. All participants underwent hormone analysis, a sniff-bottle smell test, and gadolinium-enhanced MR imaging. Changes in the hypothalamic-hypophyseal region and the rhinencephalon were evaluated.

RESULTS

MR imaging revealed intracranial morphologic changes in all patients on plain T1-weighted sections. Seventeen patients with KS demonstrated aplasia of an olfactory bulb; one olfactory sulcus was absent in six, rudimentary in four, and normal in eight. Olfactory bulbs were present in all 10 IHH patients and three showed one slightly hypoplastic bulb. Ten patients with KS and three with IHH showed an enlarged paranasal sinus system. Further MR findings were similar.

CONCLUSION

MR imaging demonstrates abnormalities of the rhinencephalon present in KS patients and occasionally absent in IHH patients.

CT of the "Tegernsee Giant": juvenile gigantism and polyostotic fibrous dysplasia

We report the radiological findings in the unusual case of the Bavarian "Tegernsee Giant." With conventional radiography, CT, and histologic examination, we succeeded in diagnosing two disorders: The Tegernsee Giant suffered from (a) juvenile gigantism caused by a growth hormone-secreting tumor of the pituitary gland and (b) a polyostotic form of fibrous dysplasia of the skull and multiple bones particularly on the left side of the body.

Ergonomic education for nursing students

An educational package of common ergonomic training as well as behavioural training was implemented in nursing education. The teaching methods also had the aim of increasing students' awareness of the importance of total work environment for the prevention of back injuries. The experimental group was, on the whole, more pleased with their education than the control group. The experimental group judged their ability to analyse the work environment higher than the control group did. Observations in some practical work-tasks showed that students from the experimental group worked in physically more favourable positions with less strain on the body.

MRI in pre- and postoperative assessment of tracheal stenosis due to pulmonary artery sling

OBJECTIVE

To evaluate the potential of MRI in the assessment of tracheal stenosis due to tracheal or vascular malformations, 45 children with severe respiratory distress were examined prospectively during a period of 1 year. Five of these children had tracheal stenosis due to a sling left pulmonary artery (SLPA).

MATERIALS AND METHODS

Magnetic resonance examinations of the anesthetized children were performed with a 1.5 T Siemens MR imager using electrocardiographically gated T1-weighted SE sequences in transverse and sagittal slice orientations. Slice thickness was 3 mm and each sequence was repeated after shifting the slice position by 1 mm. Monitoring during the examinations included ECG, oscillatory blood pressure, respiratory rate, and oxygen concentration. Magnetic resonance findings were compared with esophagography, selective pulmonary angiography, bronchoscopy, Doppler sonography, and surgery. All examinations were repeated after surgical therapy to assess the improvement in tracheal stenoses and the patency of the ligated and reimplanted left pulmonary arteries.

RESULTS

Magnetic resonance imaging clearly revealed the course of the SLPA and its topographic relationship to the trachea as well as the coexistence of cardiovascular and tracheobronchial or esophageal malformations. The degree and length of tracheal stenoses, which were measured in the pre- and postoperative axial slices and graphically displayed, as well as the angles of the right and left main stem bronchi, could be accurately determined.

CONCLUSION

Magnetic resonance imaging in combination with bronchoscopy yielded the necessary and sufficient information for diagnosis and aided the surgeon in planning operative strategy and in postoperative follow-up.

Skull base tumors: gadodiamide injection--enhanced MR imaging--drop-out effect in the early enhancement pattern of paragangliomas versus different tumors

A phase III trial was conducted in 40 patients with known or suspected skull base tumors to evaluate the safety and efficacy of high-dose gadodiamide injection for use as a paramagnetic contrast medium in conventional and dynamic magnetic resonance (MR) imaging. Contrast material enhancement was assessed dynamically with use of a gradient-recalled sequence. The time-intensity curve of selected regions of interest showed a reproducible dropout effect in the form of a dip in the curve during the early enhancement of the sigmoid sinus and jugular bulb; the same phenomenon was observed in all glomus tumors of the skull base, regardless of size or location. In contrast, schwannomas, meningiomas, and a variety of other lesions showed a continuous increase in the time-intensity curve. The drop-out sign, which is probably a result of a paramagnetic phenomenon during the early phase of enhancement, seems to be specific for glomus tumors. High-dose gadodiamide injection may show a specific dynamic pattern for glomus tumors, allowing differentiation from other tumors of the middle and posterior skull base.

Recombinant vaccinia viruses expressing GP46/M-2 protect against Leishmania infection

Leishmania is a genus of parasitic protozoa capable of causing a spectrum of human diseases. The GP46/M-2 membrane glycoprotein has been demonstrated in a murine model system to elicit a protective immune response against infection with Leishmania amazonensis; in highly susceptible BALB/c mice, immunization leads to significant protection against infection. In the present study, for induction of long-term immunological effects, two recombinant vaccinia viruses, derived from the wild type and attenuated variant 48-7 and expressing the GP46/M-2 protein, were constructed; to ensure safety, we used the attenuated vaccinia virus mutant (48-7) as a live vector. Susceptible BALB/c mice immunized with either GP46/M-2-recombinant vaccinia virus were significantly protected against infection with L. amazonensis; 45 to 76% of the animals were completely protected (sterile) against a challenge inoculum of 10(3) infective organisms. The protectively immunized animals demonstrated T- and B-cell-dependent immunological responses; both lymphokine responses as well as antibody responses and long-term memory are indicative of T-cell activation. This first report of the use of a recombinant vaccinia virus to induce protection against a Leishmania infection indicates that recombinant vaccinia viruses should be of value in the design of a safe and effective vaccine against this parasitic disease.

Three-dimensional MR reconstruction images of skull base tumors

Forty-eight patients with skull base tumors were evaluated prospectively with T1-weighted spin-echo two-dimensional (2D) magnetic resonance (MR) sequences, a three-dimensional (3D) MR TurboFLASH (fast low-angle shot) sequence, and a 3D reconstruction window technique. All patients underwent surgery with histopathologic correlation, and the three MR imaging techniques were compared to assess representation of tumor margins and the topographic relationship of tumor to surrounding tissue and adjacent vasculature. The best results were obtained with standard 2D spin-echo sequences after administration of the paramagnetic contrast agent gadopentetate dimeglumine. The 2D MR sequences gave the highest contrast-to-noise ratios, with decreasing values for 3D sequences and 3D reconstructions, respectively. Nevertheless, 3D MR imaging, by virtue of its good representation of adjacent structures, aided surgeons in planning surgical intervention. This study presents the technical features of 3D imaging of the skull base, the choices involved in its implementation, and its potential clinical applications.

Third cranial nerve palsy caused by gummatous neurosyphilis: MR findings

The clinical and MR findings in an unusual case of gummatous neurosyphilis are reported. A 44-year-old woman suffering from diplopia and right-sided headaches was admitted. Physical examination and routine laboratory parameters were normal except for a third-nerve palsy. MR images revealed a contrast-enhancing lesion of the upper brain stem and third cranial nerve. Differential diagnosis included neuroma of the third cranial nerve, as well as neurosarcoidosis and other inflammatory processes. Serologic tests and lumbar puncture revealed the presence of active syphilis. After intravenous treatment with penicillin G, follow-up MR examinations showed diminishing size of the lesion with its complete resolution within 3 months.

MR and MR angiography of Sturge-Weber syndrome

PURPOSE

To assess the potential of magnetic resonance angiography (MRA) as an adjunct to spin-echo sequences in evaluating the cerebral vascular anomalies seen in Sturge-Weber syndrome.

METHODS

Four pediatric patients with Sturge-Weber syndrome were evaluated with conventional MR imaging and with arterial and venous MRA. Resultant images were evaluated for evidence of volume loss, cortical enhancement, vascular anomalies, and enlarged choroid plexus.

RESULTS

Venous MRA revealed reduced flow of the transverse sinuses and jugular veins, prominent deep collateral venous system, and a lack of superficial cortical veins. Arterial MRA, performed in all cases, revealed a reduced flow signal from the left middle cerebral artery in one hemiparetic patient and angiomatous changes of high branches of a middle cerebral artery in two patients.

CONCLUSION

Arterial and, in particular, venous MRA can be useful adjuncts to standard spin-echo sequences in diagnosing Sturge-Weber syndrome.

T helper 1 (Th1) functional phenotype of human myelin basic protein-specific T lymphocytes

Multiple sclerosis (MS) is widely accepted as an autoimmune disease with myelin basic protein (MBP) a candidate autoantigen. In the current report, human T cell lines specific for an immunodominant region of MBP were shown to have a functional phenotype similar to T helper 1 (Th1) inflammatory cells of the mouse on the basis of their antigen-specific cytotoxic activity and production of interferon-gamma and lymphotoxin/tumor necrosis factor-alpha, but not interleukin-4. In experimental allergic encephalomyelitis (EAE), a proposed animal model for MS, MBP-specific T cell lines which mediate disease are of the Th1 subtype. Thus, MBP-specific T cells in humans exist which are phenotypically similar to MBP-specific encephalitogenic T cells in murine EAE.

MR angiography in children with cerebral neurovascular diseases: findings in 31 cases

OBJECTIVE

We evaluated the suitability of MR angiography for routine use in children with suspected intracranial vascular disease.

SUBJECTS AND METHODS

Thirty-one children, 6 months to 14 years old, with intracranial lesions or clinically suspected vascular malformations were studied prospectively with conventional MR imaging and time-of-flight MR angiography. In nine cases, MR angiographic findings were verified with digital subtraction angiography or conventional angiography. All MR studies were performed on a 1.5-T MR system using a circularly polarized head coil.

RESULTS

Arterial MR angiography, performed in 24 cases, revealed congenital abnormalities of the arterial vessels in 20 cases. Vessel stenosis was observed in nine patients, and displacement of intracranial arteries due to tumors could be seen in 10 patients. Seven children had no abnormal findings. Venous MR angiography was performed in seven children, with depiction of sinus thrombosis in six cases. The comparative analysis of MR angiography and digital subtraction angiography showed equivalent results in nine patients; in one patient the degree of stenosis was overestimated with MR angiography.

CONCLUSION

MR angiography, when combined with MR imaging, reveals information about soft-tissue and vascular structures in a single setting. At this point, MR angiography can replace invasive conventional angiography or digital subtraction angiography only in selected cases because of software and hardware limitations. Arterial or venous MR angiography can be helpful as an additional scan in MR examinations of children with suspected cerebral neurovascular diseases, and its noninvasive nature makes it well suited for routine use in children.

Incremental hydraulic jaw opener for MR imaging of the temporomandibular joint

Magnetic resonance (MR) imaging in the open- and closed-mouth positions is the method of choice for visualizing the temporomandibular joint (TMJ). To analyze the TMJ in response to various degrees of mouth opening, the authors constructed a hydraulic incremental jaw opener. This apparatus enables obtaining of reproducible and stable positions of TMJ articulation. With modified gradient pulse sequences, the technique yields good spatial resolution of joint anatomy, including that of the articular disk. The application of a cine program allows cinematographic display of TMJ motion, which in conjunction with static open- and closed-mouth views can be useful in the diagnosis of TMJ dysfunction. The authors used the incremental jaw opener to examine the disk-condyle complex at each open-mouth position, with particular attention to extreme open-mouth positions.