The novel behaviour of interactions between Ni2+ ion and human or bovine serum albumin

We discovered a series of novel behaviours of interactions between Ni2+ ion and human or bovine serum albumin. Our results indicated that there exist two closely neighbouring identical prior binding sites in the binding of human or bovine serum albumin with Ni2+ ions, not only one. It is very likely that, after the binding of the first Ni2+ ion, an induced slow conformational transition happens, which leads to the binding of the second Ni2+ ion and shows itself as a hysteretic effect for a process of non-enzymic protein binding with metal ions. As the concentrations of the 1:1 (molar ratio of Ni2+ ion to protein) system increase, an increasing hypochromic effect is observed. Such a hypochromic effect has not been reported previously; however, it is in accord with the mechanism of dipole-dipole interactions between the electric dipole transition moments of chromophores.

Acute and chronic respiratory effects of sodium borate particulate exposures

This study examined work-related chronic abnormality in pulmonary function and work-related acute irritant symptoms associated with exposure to borate dust in mining and processing operations. Chronic effects were examined by pulmonary function at the beginning and end of a 7-year interval. Time-specific estimates of sodium borate particulate exposures were used to estimate cumulative exposure during the study interval. Change in pulmonary function over the 7 years was found unrelated to the estimate of cumulative exposure during that interval. Exposure-response associations also were examined with respect to short-term peak exposures and incidence of five symptoms of acute respiratory irritation. Hourly measures of health outcome and continuous measures of particulate exposure were made on each subject throughout the day. Whenever a subject reported one of the irritant symptoms, a symptom intensity score was also recorded along with the approximate time of onset. The findings indicated that exposure-response relationships were present for each of the specific symptoms at several symptom intensity levels. The associations were present when exposure was estimated by both day-long and short-term (15-min) time-weighted average exposures. Associations persisted after taking account of smoking, age, and the presence of a common cold. No significant difference in response rate was found between workers exposed to different types of sodium borate dusts.

[Relation between histo-compatibility antigen immunogenetics and pregnancy induced hypertension]

Fourty cases with pregnancy induced hypertension (PIH) and 100 normal pregnant women were selected for this study. The distribution of histo-compatibility antigen D region (HLA-DR) frequency, the frequency of homozygosity and the HLA-DR antigens sharing between partners were investigated. The results showed that the frequency of HLA-DR4 was significantly higher in PIH than that in normal pregnancy (P < 0.001). There was a very high DR antigen sharing between partners in PIH as compared to normal pregnancy (P < 0.01), specially obvious in the frequency of DR4 antigen sharing in PIH (P < 0.0001). There was, however, no significant difference in the frequency of homozygosity or heterozygosity between HLA-DR and DR4 locus. This study suggested that HLA-DR4 may be related to the genetic susceptibility of PIH. This correlation is presumably due to a linkage imbalance of susceptible gene of PIH and DR4, but whether DR4 acts directly as an immunodeficient gene remains to be determined.

Spectroscopic imaging of circular voxels with a two-dimensional Fourier-series window technique

Spatial localization with the spectroscopic imaging technique is normally implemented with the Fourier-transform approach, yielding rectangular voxels, with potentially significant cross-voxel contamination. Multidimensional Fourier-series window (FSW) is an alternate approach that generates single voxels of predetermined shape, with minimal out-of-voxel contamination. The spatial location of the voxel is shifted by means of postacquisition processing. A two-dimensional circular voxel is introduced, which for many in vivo applications is a good match of the region of interest. Phantom images illustrate the spatial distribution of signal intensity within the circular FSW voxels. Phantom spectroscopic studies show excellent spatial localization, with no detectable out-of-voxel contamination. The circular FSW voxel approach is implemented in human and animal model studies, demonstrating the technique's utility. This arbitrary shape approach can be extended to three dimensions, defining, for example, cylinders, spheres, or ellipsoids.

A new T2 preparation technique for ultrafast gradient-echo sequence

The T2 contrast in images obtained with driven equilibrium (90degreesx-180degreesx-90degreesx) prepared ultrafast gradient-echo sequence is compromised by the longitudinal magnetization build-up after the second 90degreesx pulse, which does not carry T2 information. This paper describes a new T2 contrast preparation technique for ultrafast gradient-echo sequence that suppresses the signal arising from the build-up. By dephasing in the preparation and rephasing in the acquisition of the gradient echoes, the new technique eliminates signals that are not dictated by the T2 contrast in a driven-equilibrium approach. Consequently, it generates an image that is essentially T2-weighted. Phantom and in vivo experiments were conducted to validate the technique and to demonstrate its clinical utility. These studies indicate that the technique works properly and can be used for in vivo studies.

Cloning and sequencing of the cDNAs encoding two alternative splicing-derived variants of the alpha subunit of the granulocyte-macrophage colony-stimulating factor receptor

Two distinct cDNA clones, corresponding to alternative mRNA splicing variants of the alpha subunit of the granulocyte-macrophage colony-stimulating factor receptor (GM-CSF-R alpha) were isolated from human blood mononuclear cells by RT-PCR. The first one lacks 179 bp, and the second one lacks 136 bp of the major variant, GM-CSF-R alpha 1. Both of variants result in shifts in the reading frame and are expected to encode 377- and 285-amino-acid membrane anchoring and soluble receptor isoforms, respectively.

Restoration of intracellular drug accumulation in MDR cell line K562r does not mean reversal of its drug resistance

Our purpose was to test whether drug sensitivity and drug accumulation in MDR cell erythroleukemic K562r could be restored by incubating cells with 3 anthracycline antibiotics in combination. Drug sensitivities of cells were assessed with MTT assay, in which doxorubicin, epirubicin, daunorubicin, or the 3-drug mixture was applied with concentrations ranging from 1 to 3125 ng.ml-1. The IC50 of K562r cells were 1.0, 1.0, 0.1, and 0.2 microgram.ml-1, respectively, about 22, 16, 10, and 20 times higher than those of K562 cells. After cells were exposed to doxorubicin (2-32 micrograms.ml-1) for 1 h, the drug concentrations in K562r cells were all higher than those in K562 cells. Similar results were obtained for epirubicin or daunorubicin. After 1-h incubation of cells with the 3-drug mixture (3 to 192 micrograms.ml-1), there were no considerable differences of drug accumulation between K562r and K562 cells with only 3 exceptions in 21 groups. It is concluded that restoration of intracellular drug accumulation in MDR cell line K562r was not correlated with reversal of its drug resistances.

Investigation of meperidine and its metabolites in urine of an addict by gas chromatography-flame ionization detection and gas chromatography-mass spectrometry

A gas chromatographic method with flame ionization detection (FID) for the quantitative analysis of meperidine and mass spectrometry (MS) for the qualitative analyses of meperidine and its metabolites in urine was established. Meperidine, normeperidine and acetyl normeperidine in urine were extracted with ether. Free and conjugated meperidinic and normeperidinic acids in urine, which are hydrophillic, were hydrolyzed by acid, esterified with methanol and derivatized with acetic anhydride. Meperidine and its four metabolites were identified by GC-MS. Meperidine was measured by GC-FID during 72 h after intramuscular administration of meperidine to an addict.

Association of fibroblast growth factor receptor-1 with c-Src correlates with association between c-Src and cortactin

The initiation of maximal DNA synthesis by fibroblast growth factor (FGF)-1 requires the presence of the growth factor during the entire G0 to G1 transition period of the cell cycle (Zhan, X., Hu, X., Friesel, R., and Maciag, T. (1993) J. Biol. Chem. 268, 9611-9620). During this time, the phosphorylation of several novel proteins on tyrosine residues occurs, and one of these phosphotyrosyl-containing proteins has been characterized as the murine homolog of the chicken cortactin gene (Zhan, X., Hu, X., Hampton, B., Burgess, W.H., Friesel, R., and Maciag, T. (1993) J. Biol. Chem. 268, 24427-24431), a putative substrate for v-Src. We have examined the possibility that FGF-1 employs c-Src or Src-like kinases as signaling intermediates during the mid and late G1 phase of the NIH 3T3 cell cycle using immunoprecipitation and immunoblot analysis. We have demonstrated that c-Src can associate with cortactin in a FGF-1-dependent manner. We have also demonstrated that a monoclonal antibody prepared against FGF receptor (R)-1 is able to co-precipitate Src-related proteins in lysates from FGF-1-treated NIH 3T3 cells. Furthermore, a kinase-active form of FGFR-1 expressed in a bacterial system was also able to associate with Src kinases in a manner dependent on the phosphorylation status of the FGFR-1 protein. Lastly, the Src homology (SH)-2 domain of v-Src was able to recognize a recombinant form of FGFR-1. Because (i) the association between FGFR-1 and Src-like kinases exhibits kinetics similar to those observed between the Src kinases and cortactin and (ii) the Src-SH2 domain is likely to be involved in the association with FGFR-1, we propose that the association of c-Src with activated FGF receptors may be responsible for the tyrosine phosphorylation of cortactin during the mid to late G1 phase of the cell cycle.

A rating instrument for the evaluation of in-patient rehabilitation programmes in China. Results of reliability and validity testing

To objectively evaluate in-patient rehabilitation programmes in China, we developed a new rating scale: the Inpatient Psychiatric Rehabilitation Outcome Scale (IPROS). The scale has five subscales: performance in occupational therapy, daily activities, socialisation, personal hygiene, and level of interest in external events. Evaluators (physicians or nurses) observe patients for one week before coding items on a five-point scale. Comparison of four independent evaluators' results for 32 schizophrenic patients assessed on two separate occasions indicated that the inter-rater and test-retest reliability for the overall IPROS score and for the five subscale scores was excellent (all ICC values > or = 0.973). Validity was evaluated by comparing IPROS results with those of five other independently assessed clinical measures for 101 chronic schizophrenic patients before and after a six-month rehabilitation programme; concurrent validity and longitudinal validity were satisfactory (correlation coefficients 0.37-0.81, all P values < 0.01).

Determination of trace amounts of urea by using flow injection with chemiluminescence detection

Reaction between urea and hypobromite in alkaline solution was found to produce chemiluminescence with a maximum wavelength at 510 nm. A simple chemiluminescence detection method was used for the determination of urea in human urine and natural aqueous samples, which combined this chemiluminescence reaction with a flow injection analysis system. The relative standard deviation for 5 x 10(-7) mol dm-3 urea is 1.9% (n = 6), and the detection limit is 9.0 x 10(-8) mol dm-3 (3Sr). As this chemiluminescence reaction is very fast, a double concentric tube mixer connected directly to the chemiluminescence cell was used to mix urea solution and hypobromite solution. Alkylamines, carboxylic acids and most amino acids do not interfere in the determination. Ammonium ion interferes, but the sensitivity for ammonium ion is only 1% of that for urea. The interference from ammonium ion was removed sufficiently by using an on-line cation-exchange column.

Functional limitations and recovery in children with severe trauma: a one-year follow-up

To examine functional limitations, recovery rates, and association with Injury Severity Scores (ISSs), we followed 92 children with severe trauma and 59 control subjects with appendicitis at 6 months and 1 year after discharge. Physical health status was assessed by the Rand Health Insurance Study instrument. Overall, 73% and 55% of trauma patients had one or more functional limitations at 6 months and 1 year, respectively, in contrast to 14% and 9% of the controls. Overall functional status of the trauma patients improved by 22% in the first 6 months and 24% in the second. Much higher recovery rates (73% and 46%) were noted for self care. Although ISS did not correlate with overall functional status, higher ISSs were related to impairment in patients whose principal injury was to the head or the face-chest-abdomen but not in those whose principal injury was to an extremity. This study shows that many children with severe trauma are left with disabilities. Recovery rates are not uniform but depend on type of limitation. Functional impairment and recovery are related more to the body parts involved than to ISS.

Family-based intervention for schizophrenic patients in China. A randomised controlled trial

BACKGROUND

We developed and evaluated a comprehensive, ongoing intervention for families of schizophrenic patients appropriate for China's complex family relationships and unique social environment.

METHOD

Sixty-three DSM-III-R schizophrenic patients living with family members were enrolled when admitted to hospital and randomly assigned to receive standard care or a family-based intervention that included monthly 45-minute counselling sessions focused on the management of social and occupational problems, medication management, family education, family group meetings, and crisis intervention.

RESULTS

At 6, 12, and 18-month follow-ups by blind evaluators, the proportion of subjects rehospitalised was lower, the duration of rehospitalisation was shorter, and the duration of employment was longer in the experimental group than in the control group; these differences were statistically significant at the 12 and 18-month follow-ups and were not explained by differences in drug compliance. Family intervention was associated with significantly lower levels of family burden.

CONCLUSIONS

This intervention is less costly than standard treatment, is suitable for urban families of schizophrenic patients in China and feasible given the constraints of the Chinese mental health system.

Equilibrium dialysis of metal-serum albumin. I. Successive stability constants of Zn(II)-serum albumin and the Zn(2+)-induced cross-linking self-association

The binding of Zn(II) to human serum albumin (HSA) and bovine serum albumin (BSA) was intensively studied by equilibrium dialysis. The successive stability constants were obtained by least-squares fitting. For both the Zn(II)-HSA and Zn(II)-BSA systems, the successive stability constants are basically similar, though such constants for the latter generally slightly larger than those for the former; the order of magnitude of K1 and K2 was found to be approximately 10(5) M-1. The twelve binding sites found for Zn(II)-HSA and fourteen binding sites for Zn(II)-BSA can be divided into three and two different sets, respectively, but in both systems, there exist approximately three identical strongest binding sites. The binding equilibrium of Zn(II)-HSA markedly depends on the concentration of HSA. The type of Scatchard plots indicates the existence of the Zn(2+)-induced cross-linking self-association of HSA, which was found from Wyman plots to be the strongest at a concentration of Zn2+ in the range (4-6) x 10(-6) M. The maximum of the apparent self-association constants k2 so obtained was approximately 2.6 x 10(4) M-1. Such a self-association mechanism and the order of magnitude of K1 and K2 both to some extent support the inference that the zinc group ions are bound to the cysteinyl sulphur atoms.

Fatal and non-fatal childhood injuries in Metropolitan Toronto, 1986-1991

The distribution of the cause, rate and nature of fatal and major non-fatal injuries in children living in Metropolitan Toronto and their trends from 1986 to 1991 were systematically reviewed from hospital discharge records and coroner's records. A total of 11,024 non-fatal injuries, of which falls were the leading cause (45%), and 133 fatal injuries, of which intentional injury (21%) was the principal cause, occurred during the six-year study period. The non-fatal injury rate dropped 23%, from 567 to 436 per 100,000 children. Mortality rates also fell during the study period. However, injuries to motor vehicle occupants and drownings increased considerably. Fractures of various kinds were the most common clinical diagnosis. Protecting children in motor vehicles by promoting the use of proper restraints and preventing injuries caused by falls and drowning should be high priorities for childhood injury prevention in Metropolitan Toronto.

Hepatic adenoma: report of three cases and review of the literature

Pathologically confirmed hepatic adenoma (HA) was observed in two women who were not using contraceptives and one 60-year-old man. All three cases had a mass in the right lobe of the liver and almost normal laboratory results. One case that had a movable pedunculated mass mimicked an extrahepatic tumor preoperatively, and two cases associated with acute abdominal pain resulting from intratumor hemorrhage were misdiagnosed as hepatoma and given interventional therapy prior to liver biopsy. In hepatic arterial DSA of two cases, the tumor appeared as hypervascular with peripheral blood supply and regularly parallel branches coursing centrally. On CT scans, the tumor appeared to be surrounded by a low-density ring in two cases, and an intratumor hyperdense area of fresh blood was noted in one case. Analysis of the three cases in this series and a review of the literature indicated that if the DSA and CT findings described above were revealed in a patient, particularly a young woman, with a mass of the right lobe of the liver (with or without acute abdominal pain) and normal laboratory results, HA should be strongly suspected, and CT-guided biopsy should be performed for pathological diagnosis, particularly when an equivocal diagnosis is made.

[A study of prostaglandine E(2) level in root canal fluid of patients with periapical lesions]

It has been reported that there is close relationship between prostaglandine E(PGE) and the pathogenesis of periapical lesions, In this study the root canal fluid(RCF) of 35 cases with acute,chronic and convalescent periradicular lesions were collected with assessed by the method of radioimmunoassay.The results showed:RCF-PGE(2) levels were increased with the severity of periapical lesion(P<0.01).The PGE level was highest in acute periradicular lesions,middle in chronic,and lowest in convalescent.RCF-PGE(2) levels were significantly different between either two groups of the three groups of patients(P<0.01-0.05).This study repeatedly proved that PGE(2) has certain effect in pathogenesis of periapical lesions and it is meaningful in guiding clinical therapy.It was also pointed out that RCF is one of worthwhile samples in the study of periradicular lesion.

Reduction of field of view for dynamic imaging

This paper describes a simple technique that improves the temporal resolution for certain dynamic imaging applications. The technique is based on the assumption that the image to image intensity changes sought in dynamic imaging studies are sometimes localized, and a smaller field of view can be used to reduce imaging time. Technical details and experimental results are presented. Experimental results show that this technique works reasonably well for in vivo applications.

Reduction of signal fluctuation in functional MRI using navigator echoes

Functional magnetic resonance imaging is sensitive to signal fluctuations due to physiological motion and system instability. In this paper, motion-related signal fluctuations are studied, and a method that uses navigator echoes to monitor and compensate for signal fluctuations in a gradient-echo sequence is described. The technique acquires a "navigator" signal before the application of the phase-encoding and readout gradients and corrects the phase of the subsequently acquired imaging data. This technique was implemented on a 4 Tesla whole body system and validated on normal volunteers. With this technique, temporal fluctuations in image intensity were substantially reduced and improved functional activation maps were obtained.

[Intracellular accumulation, retention, and distribution of anthracyclines in a multidrug-resistant variant K562r]

A multidrug resistant variant (K562r) of the human K562 erythroleukemia cell line was obtained in vitro by repeated exposure of these cells to vincristine. The K562r cells were resistant to vincristine, harringtonine, mitomycin C, doxorubicin, epirubicin, and daunorubicin but retained the sensitivity to methotrexate. The resistances to vincristine and anthracyclines were reversed in the presence of verapamil. Despite being 60-or over 60-fold resistances to doxorubicin, epirubicin and daunorubicin, the net intracellular uptakes of these drugs at 2 h were reduced by only 15%, 20%, and 11%, respectively in K562r cells compared to their parental line. Verapamil did not enhance drug accumulation but inhibited drug efflux in K562r cells. Though there was no significant difference of drug content in cytoplasm between K562 and K562r cells, the drug content in the nucleus of K562r cells reduced significantly compared to that in K562 cells. The lower concentrations of anthracyclines in the nucleus of K562r cells might contribute to their acquisition of drug resistance.

Accurate T1 determination from inversion recovery images: application to human brain at 4 Tesla

It is well known that the signal polarity in inversion-recovery (IR) images changes with inversion time, complicating the determination of T1. To avoid this problem, a simple subtraction method is implemented. In this method, k-space data of the longest inversion time are subtracted from the corresponding data of each inversion time. This subtraction yields IR images of same polarity, making it straightforward to derive T1 using a standard fitting routine. Phantom T1 studies with IR Turbo-FLASH images demonstrate that this technique is robust and accurate. Four Tesla T1 values of the human brain were also determined by this method to demonstrate its in vivo utility.

Potential pitfalls of functional MRI using conventional gradient-recalled echo techniques

The conventional gradient-recalled echo technique, FLASH, has widely been used for functional MRI. FLASH results at 4 T with short TEs of 10-20 ms mimic those at 1.5 T with TEs of 25-50 ms or longer. Under these conditions, large venous vessels dominate the activated area; however, the use of longer TEs at 4 T reveals activation in gray matter areas as well as large vessels. Inflow effects of large vessels can be greatly reduced with centric-reordering of phase-encoding steps and inter-image delay. Finger and toe movement paradigms show that functional activation maps are consistent with classical somatotopic maps, and are specific to the tasks. Navigator-based motion correction generates functional maps with larger activation areas by reducing physiological noise.

Current bicycle helmet ownership, use and related factors among school-aged children in metropolitan Toronto

A random digit dialing telephone survey was conducted to examine bicycle helmet ownership, use and related factors among 707 children in Metropolitan Toronto. The ownership rate was 22% and use rate 12%. Although ownership was similarly distributed by age and sex, helmet use varied considerably across age strata among boys; only about one fifth of teenaged boys who owned a helmet wore it regularly. Both parental education and annual family income were significantly associated with ownership and use. Past bicycle injuries, although increasing helmet ownership, had no positive impact on use. The strength of a parental role model was reflected in the fact that when parents owned and used a helmet, 93% of their children had a helmet and more than 80% of them always wore it. Since about half of parents are cyclists themselves, helmet promotion activities are likely to maximize their effect if they target both parents and children.

Synthesis of myristoyl CoA analogues and myristoyl peptides as inhibitors of myristoyl CoA:protein N-myristoyltransferase

To develop inhibitors of myristoyl CoA:protein N-myristoyltransferase (NMT), a series of myristoyl coenzyme A analogues and myristoyl peptides were synthesized, including S-(2-oxopentadecyl)-CoA (1), S-(2-hydroxypentadecyl)-CoA (2), S-(2-oxopentadecyl)-pantetheine (3), Myr-N-Gly-(L)-Phe (4), Myr-N-Gly-(L)-Tyr (5), and Myr-N-Gly-(L)-Asn-Ala- Ala-Ser-Ala-Arg-(NH2) (6). Biological evaluation of these compounds in an in vitro NMT enzyme assay revealed that the nonhydrolyzable acyl CoA analogue 1 was the most potent inhibitor [inhibitor dissociation constant (Ki) = 24 nM]. A preliminary structure-activity relationship study showed that the adenosine moiety and the 2-keto group in this nonhydrolyzable analogue were necessary for inhibitory activity. A possible mechanism for the inhibition of NMT by 1 was proposed, in which 1 might block the reaction at the stage of an acyl-CoA-NMT-peptide complex. Product analogues such as the myristoylated peptides 4-6 were poor inhibitors of NMT.

Steady-state free precession imaging of the inner ear

The authors describe a steady-state free precession technique for imaging the inner ear. Although the signal-to-noise ratio is not as great as with other three-dimensional MR techniques, the inherent high contrast of inner ear structures makes this a valuable technique for patients with sensorineural hearing loss and for those who refuse paramagnetic contrast material.

Simpler locally focused tomography in MR imaging

The author describes a simple technique for performing locally focused tomography with magnetic resonance imaging. In contrast to a previous technique, which utilized wave functions to represent k-space data, the one described here does not require complicated experimental design and reconstruction procedures and is easy to implement and understand. The technique is verified with an experimental study. Technical details and experimental results are presented.

Incorporation of correlated structural images in PET image reconstruction

Reports on a new method in which spatially correlated magnetic resonance (MR) or X-ray computed tomography (CT) images are employed as a source of prior information in the Bayesian reconstruction of positron emission tomography (PET) images. This new method incorporates the correlated structural images as anatomic templates which can be used for extracting information about boundaries that separate regions exhibiting different tissue characteristics. In order to avoid the possible introduction of artifacts caused by discrepancies between functional and anatomic boundaries, the authors propose a new method called the "weighted line site" method, in which a prior structural image is employed in a modified updating scheme for the boundary variable used in the iterative Bayesian reconstruction. This modified scheme is based on the joint probability of structural and functional boundaries. As to the structural information provided by CT or MR images, only those which have high joint probability with the corresponding PET data are used; whereas other boundary information that is not supported by the PET image is suppressed. The new method has been validated by computer simulation and phantom studies. The results of these validation studies indicate that this new method offers significant improvements in image quality when compared to other reconstruction algorithms, including the filtered backprojection method and the maximum likelihood approach, as well as the Bayesian method without the use of the prior boundary information.

A new strategy for spectroscopic imaging

This paper describes a new approach for reducing ringing artifacts in spectroscopic imaging (or chemical-shift imaging). The new method is aimed at reducing the signal contamination in areas of interest, due to ringing, that often arises from adjacent areas with high intensity, such as subcutaneous fat in the case of 1H spectroscopy and skeletal muscle in case of the 31P spectroscopy. The method is based on the fact that the high-intensity signals which are the major source of contamination can be captured with one or few acquisitions and the metabolite resonances in areas of interest require considerably more averaging in the data acquisition due to low signal-to-noise ratio. In order to reduce ringing and maintain adequate SNR for the metabolites, the data points in high k space are measured with one or few excitations while those in the low k space are sampled with many excitations. By virtue of this sampling scheme, the data contain more noise in the high-spatial-frequency region and direct Fourier transformation reconstruction generates a very noisy image. Therefore, a new reconstruction technique is developed for the reconstruction. This approach has been studied by simulations and its practical utility is demonstrated by an in vivo proton CSI experiment. Technical details and simulation and experimental results are presented. From these results, it is concluded that the technique is robust and can be used for in vivo applications.

Imaging at high magnetic fields: initial experiences at 4 T

This article reviews the preliminary experiences and the results obtained on the human brain at 4 T at the University of Minnesota. Anatomical and functional images are presented. Contrary to initial expectations and the early results, it is possible to obtain high-resolution images of the human brain with exquisite T1 contrast, delineating structures especially in the basal ganglia and thalamus, which were not observed clearly in 1.5-T images until now. These 4-T images are possible using a new approach that achieves maximal contrast for different T1 values at approximately the same repetition time and has built-in tolerance to variations in B1 magnitude. For functional images, the high field provides increased contribution from the venuoles and the capillary bed because the susceptibility-induced alterations in 1/T2* from these small-diameter vessels increase quadratically with the magnitude of the main field. Images obtained with short echo times at 4 T, and by implication at lower fields with correspondingly longer echo times, are expected to be dominated by contributions from large venous vessel or in-flow effects from the large arteries; such images are undesirable because of their poor spatial correspondence with actual sites of neuronal activity.

Murine cortactin is phosphorylated in response to fibroblast growth factor-1 on tyrosine residues late in the G1 phase of the BALB/c 3T3 cell cycle

We have previously reported that BALB/c 3T3 cells require a prolonged exposure to fibroblast growth factor (FGF)-1 for the stimulation of maximal DNA synthesis, and this event correlates with the tyrosine phosphorylation of novel proteins late in G1 including a protein termed p80/p85 (Zhan, X., Hu, X., Friesel, R., and Maciag, T. (1993) J. Biol. Chem. 268, 9611-9620). We have purified, sequenced, and cloned the cDNA encoding p80/p85 and report that it is the murine homolog of the chicken cortactin gene and a member of the human hematopoietic specific-1 gene family. Immunochemical analysis of m-cortactin-tyrosine phosphorylation in response to FGF-1 demonstrates a biphasic phosphorylation pattern both as a weak immediate-early and strong mid to late G1 response protein. Because the chicken cortactin gene was originally isolated as a substrate for v-Src, FGF-1 may influence the enzymatic activity of other cell-associated tyrosine kinases which utilize p80/p85 (cortactin) as a polypeptide substrate.

A new T2*-weighting technique for magnetic resonance imaging

This paper describes a method that prepares the longitudinal magnetization with T2* weighting for subsequent acquisition. The main advantage of our technique is its insensitivity to static field inhomogeneity. We have combined this approach with an ultrafast gradient-echo (Turbo-FLASH) sequence and conducted experiments on phantoms and volunteers to demonstrate its capability and utility. With such a technique a T2*-weighted image can be generated in less than a second. In the paper, the detail of the technique and experimental results are presented.

Thrombosis of the portal venous system after splenectomy for pediatric hematologic disease

Splenic, portal, or mesenteric venous thrombosis after splenectomy for hematologic disease has not been reported in the pediatric literature. It is a rare complication associated with significant morbidity and mortality in adult reports. Between 1981 and 1991, 3 patients (13-year-old boy with hereditary elliptocytosis [HE], 13-year-old boy with thalassemia intermedia [TI], and 18-year-old girl with idiopathic thrombocytopenic purpura [ITP]) presented with abdominal pain, nausea, with or without fever, at 4, 11, and 13 days postsplenectomy, respectively. Abdominal Doppler ultrasound (US) and/or computed tomography (CT) showed: (1) an intraluminal filling defect with partial obstruction to flow in the right branch of the portal vein with the remaining vessels patent (HE); (2) splenic vein thrombosis with complete occlusion of the main portal vein and proximal superior mesenteric vein (TI); and (3) complete thrombosis of the splenic vein, proximal superior mesenteric vein and portal vein (including central radicles), with retrogastric collateralization (ITP). Subsequent imaging showed either complete resolution of vascular obstruction on no treatment (patient 1), or portal venous cavernomatous transformation with hepatofugal flow after 6 months of systemic anticoagulation (patients 2 and 3), and all 3 patients are currently asymptomatic. Postoperative sonographic evaluation of a consecutive series of pediatric splenectomies for hematologic disease (n = 16), was performed at a median of 51 days (range, 3 to 124). This demonstrated one case of asymptomatic left portal venous thrombosis with subsequent recanalization in the absence of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk factors for extended disruption of family function after severe injury to a child

OBJECTIVE

To identify risk factors for long-lasting disruption of family function following pediatric trauma that can be measured at the time of trauma.

DESIGN

Prospective, exploratory study. Personal interviews were conducted at the time of admission and 6 months and 1 year after discharge.

SETTING

Level I regional pediatric trauma centre.

PARTICIPANTS

One hundred and five families (86% of those eligible) with a child admitted to hospital for severe trauma with an Abbreviated Injury Scale (AIS) score of 4 or higher or with two or more injuries in different body parts and AIS scores of 2 or higher were recruited; 13 families were lost to follow-up at 6 months or 1 year, so their data were not included in the analyses.

MAIN OUTCOME MEASURES

Family function status (normal or abnormal compared with function before the injury), demographic characteristics of the parents and child, injury severity, presence of maternal psychologic disorder, presence of child behaviour abnormality and functional status of the child.

MAIN RESULTS

At 6 months and at 1 year 41 families (45%) and 21 families (23%) respectively reported that their family lives had not returned to normal. The relative odds for disruption of family life were about five times higher (95% confidence limits [CL] 1.4 and 19.7) and four times higher (95% CL 1.1 and 14.0) for single-parent families than for families with married parents living together at 6 months and 1 year respectively. The presence of maternal psychologic disorders at admission and increased age of the injured child were also significantly associated with extended disruption of family function. Injury severity and functional status at discharge were not good predictors of family function.

CONCLUSIONS

Severe injury to a child places a heavy strain on normal family function. In particular, single parents and parents experiencing mental or emotional problems at the acute stage of the injury need help in coping with their reactions to the trauma and may benefit from individual or group counseling.

Experimental and clinical investigations of human insoluble bone matrix gelatin. A report of 24 cases

Human bone matrix gelatin (hBMG) was implanted into the quadriceps muscles of mice to determine its osteoinductive activity and immune responses. The host mouse muscle assay reacted positively to the hBMG, providing an experimental basis for clinical application. At two weeks after implantation, cartilage was produced in the mouse muscle, and new bone and bone marrow were formed at three to four weeks after implantation. Human bone matrix gelatin, which was thus shown to have osteoinductive activity, was subsequently implanted in 24 patients. Generally, the bone defects were filled with new bone tissue with increased density within two to four months after operation. Nonunion and delayed unions were healed at two to six months after surgery.

Functional magnetic resonance imaging of Broca's area during internal speech

Conventional gradient-echo magnetic resonance imaging (MRI) at 4 Tesla was used successfully to study the activity of Broca's area during internal speech word generation in healthy right-handed volunteers. Activity was demonstrated in the internal gray matter surrounding the ascending ramus of the lateral sulcus, deep to the cortical surface representation of Broca's area, in all the subjects. These studies demonstrate the capability of functional MRI to non-invasively map language related cognitive functions. Such functional mapping has value for both the study of basic neuroscience and neurosurgical planning.