Monitoring of donor/recipient T-cell engraftment kinetics in myeloablative allogeneic stem cell transplantation using short tandem repeat amplification from cell lysates

Molecular monitoring of donor/recipient T-cell kinetics early post-transplant can provide clues to the immunological events that govern host-versus-graft reaction (HVGR) and graft versus-host-disease (GVHD). We have previously used fluorescence in situ hybridization (FISH) with X and Y probes to monitor recipient T (R-T) cell clearance early after myeloablative allogeneic stem cell transplantation (ASCT). We demonstrated that impaired clearance of residual host-T-cells in the early days post-transplant was associated with graft rejection, while enhanced clearance could be an indicator of increased donor anti-host alloreactivity and predictive of acute GVHD. Although FISH is the most accurate quantitative molecular tool for the determination of the exact donor/recipient-T-cell numbers at any time points post-transplant, it has the disadvantage of being limited to sex mismatched donor/recipient pairs. Our goal was to develop a molecular approach that, irrespective of gender, would be comparable to FISH in accurately determining host residual T-cell clearance after myeloablative conditioning for ASCT. We have genotyped DNA from cell lysates using polymerase chain reaction (PCR) amplification of short tandem repeats (STR) with fluorescently labeled oligonucleotide primers, and used the Genescan 672 software for accurate quantitative analysis of the amplified alleles. Here, we show that this approach allowed us to achieve in T-cells accurate quantitative analyses of amplified donor/recipient alleles in sex matched patients on days +5, +8 and +12 post-transplant, despite severe leukopenia.

Tumour surgery of the upper cervical spine--a retrospective study of 13 cases

A series of tumour cases of the upper cervical spine who we had treated was analysed retrospectively with respect to surgical complications, quality of life and survival, 13 patients (mean age 56 years, metastases 6, plasmocytomas 3, chordomas 2, histiocytosis 1, aneurysmal bone cyst 1) with tumours of the upper cervical spine (C2 n = 7, C2 and C3 n = 4, C3 n = 2) were treated during an 8-year period. A total of 16 operations were carried out with ten one-step procedures and three two step-procedures. Eight extra-oral, one transoral, three dorsal and, in one case, a combined dorsal and extra-oral tumour removal were performed. Four dorsal stabilisation's, four ventral platings and two combined ventral platings plus dorsal fixations and eight vertebral body replacements were carried out. The neurological status and the quality of life were analysed preoperatively and during the follow-up examinations. Flexionextension radiographs were taken during follow-up. There was no operative mortality. The transient morbidity was 8%. The operative intervention significantly improved the quality of life in all patients during the follow-up visits (mean: 20 months). No instability was seen. The average survival time of all patients was 23 months. Six patients died following the operation after a mean time of 28 (4-64) months. Tumour removal in the upper cervical spine using individually modified surgical strategies based on an approach combining tumour location, stabilisation and vertebral body replacement significantly increases the time of survival and quality of life with an acceptable surgical risk for complications.

A fluorometric method for the differentiation of algal populations in vivo and in situ

Fingerprints of excitation spectra of chlorophyll (Chl) fluorescence can be used to differentiate 'spectral groups' of microalgae in vivo and in situ in, for example, vertical profiles within a few seconds. The investigated spectral groups of algae (green group, Chlorophyta; blue, Cyanobacteria; brown, Heterokontophyta, Haptophyta, Dinophyta; mixed, Cryptophyta) are each characterised by a specific composition of photosynthetic antenna pigments and, consequently, by a specific excitation spectrum of the Chl fluorescence. Particularly relevant are Chl a, Chl c, phycocyanobilin, phycoerythrobilin, fucoxanthin and peridinin. A laboratory-based instrument and a submersible instrument were constructed containing light-emitting diodes to excite Chl fluorescence in five distinct wavelength ranges. Norm spectra were determined for the four spectral algal groups (several species per group). Using these norm spectra and the actual five-point excitation spectrum of a water sample, a separate estimate of the respective Chl concentration is rapidly obtained for each algal group. The results of dilution experiments are presented. In vivo and in situ measurements are compared with results obtained by HPLC analysis. Depth profiles of the distribution of spectral algal groups taken over a time period of few seconds are shown. The method for algae differentiation described here opens up new research areas, monitoring and supervision tasks related to photosynthetic primary production in aquatic environments.

Violent behaviors in early adolescent minority youth: results from a "middle school youth risk behavior survey"

OBJECTIVES

To describe the prevalence and characteristics of violence and violence-related behaviors among six populations of U.S. minority adolescents in grades 6-8.

METHODS

Six thousand four hundred non-White adolescents were recruited from six sites that were part of a collaborative project. Surveys were administered either during the school day or at community facilities. All students at each site were asked 10 questions about recent violence-related behaviors (including use of threats, fighting, weapon carrying, and weapon use). Prevalence of each violence-related behavior was reported within and across sites, and stratified by race/ethnicity, gender, age, and other characteristics expected to influence the behaviors.

RESULTS

Sixty-six percent (66%) of the middle school students sampled reported being involved in some type of recent fighting and/or weapon-related behaviors. Sixty-one percent (61%) indicated some form of fighting behavior in the past 3 months (threatening to beat someone up, physical fighting, and/or being hurt in a fight). Thirty percent (30%) of participating youth reported one or more weapon-related behaviors (threatening to use a weapon, carrying a weapon, using a weapon, and/or being cut, stabbed or shot at). Reported gun carrying among males varied depending upon site, but was as high as 20%. Grade in school was positively associated with reported violent behaviors. Adolescents who reported living full-time with a parent or parent figure, and those who reported religious observance or beliefs, were less likely to report violence involvement. All violence-related behaviors were more common among male than female adolescents.

CONCLUSIONS

Violence prevention efforts should begin in elementary school and continue throughout adolescence. Programs should be prepared to provide services or referrals to victims of violence, implement programs tailored toward females as well as males, and build partnerships with churches and other community organizations in which youth are involved.

Characterization of a mutation in the lens-specific MP70 encoding gene of the mouse leading to a dominant cataract

During an ethylnitrosourea mutagenesis screen, Aey5, a new mouse mutation exhibiting an autosomal dominant congenital cataract was isolated. The cataractous phenotype is visible at the eye opening and progresses to a nuclear and zonular cataract at 2 months of age with no difference in onset or severity between heterozygous and homozygous mutants. Histological analysis revealed that fiber cell differentiation continues at the lens bow region, but the cell nuclei do not degrade normally and remain in the deeper cortex. Further, the lens nucleus has clefts of various sizes while the remainder of the eye was morphologically normal. The mutation was mapped to chromosome 3 between the markers D3Mit101 and D3Mit77 near the connexin encoding genes Gja5 and Gja8. Sequence analysis revealed no differences in the Gja5 gene, but identified a T-->C mutation at position 191 in the Gja8 gene, which was confirmed by an additional Mva 12691 restriction site in the genomic DNA of homozygous mutants. This mutation results in Val-->Ala substitution at codon 64 of connexin50 (Cx50) also known as lens membrane protein 70 (MP70). Aey5 represents the second dominant mouse cataract mutant affecting Cx50, a membrane protein preferentially expressed in the lens. Since both mutations affect similar regions in the first extracellular domain this region appears to be critically important for its function in lens transparency.

Oblique stepwise rise and growth of the Tibet plateau

Two end member models of how the high elevations in Tibet formed are (i) continuous thickening and widespread viscous flow of the crust and mantle of the entire plateau and (ii) time-dependent, localized shear between coherent lithospheric blocks. Recent studies of Cenozoic deformation, magmatism, and seismic structure lend support to the latter. Since India collided with Asia approximately 55 million years ago, the rise of the high Tibetan plateau likely occurred in three main steps, by successive growth and uplift of 300- to 500-kilometer-wide crustal thrust-wedges. The crust thickened, while the mantle, decoupled beneath gently dipping shear zones, did not. Sediment infilling, bathtub-like, of dammed intermontane basins formed flat high plains at each step. The existence of magmatic belts younging northward implies that slabs of Asian mantle subducted one after another under ranges north of the Himalayas. Subduction was oblique and accompanied by extrusion along the left lateral strike-slip faults that slice Tibet's east side. These mechanisms, akin to plate tectonics hidden by thickening crust, with slip-partitioning, account for the dominant growth of the Tibet Plateau toward the east and northeast.

Cochlear implant assessment: imaging issues

Cochlear implants are electronic auditory prostheses used to rehabilitate deafened persons who have lost their hair cells. They are partly worn externally and partly implanted in the ear. They provide a direct stimulation of the spiral ganglion cells of the cochlear nerve by bypassing the destroyed hair cells. The objectives of this article are to summarise what head and neck surgeons need to know before cochlear implantation and to describe the imaging study protocol used and anomalies to look for. A few explanations are resumed about placement of a brainstem implant.

Characterization of a new, dominant V124E mutation in the mouse alphaA-crystallin-encoding gene

PURPOSE

During an ethylnitrosourea (ENU) mutagenesis screening, mice were tested for the occurrence of dominant cataracts. The purpose of the study was morphologic description, mapping of the mutant gene, and characterization of the underlying molecular lesion in a particular mutant, Aey7.

METHODS

Isolated lenses were photographed and histologic sections of the eye were analyzed according to standard procedures. Linkage analysis was performed with a set of microsatellite markers covering all autosomal chromosomes. cDNA was amplified after reverse transcription of lens mRNA. For PCR, cDNA or genomic DNA was used as a template.

RESULTS

Nuclear opacity and posterior suture anomaly were visible at eye opening and progressed to a nuclear and zonular cataract at 2 months of age. The opacity as well as the microphthalmia was more pronounced in the homozygotes than in the heterozygotes. The mutation was mapped to chromosome 17 between the markers D17Mit133 and D17Mit180. This position made the alphaA-crystallin-encoding gene (Cryaa) an excellent candidate gene. Sequence analysis revealed a mutation of a T to an A at position 371 in the Cryaa cDNA. The mutation was confirmed by an additional MnlI restriction site in the genomic DNA of homozygous mutants leading to replacement of Val with Glu at codon 124 affecting the C-terminal region of the alphaA-crystallin.

CONCLUSIONS

The Aey7 mutant represents the first dominant mouse cataract mutation affecting the Cryaa gene. The mutation leads to progressive opacification of the lens. Compared with the beta- and gamma-crystallin-encoding genes, mutations in the alpha-crystallin-encoding genes are rare.

Attachment styles and personality disorders as predictors of symptom course

Adult attachment styles and personality disorders (PDs) show some conceptual and empirical overlap and both may complicate the course of symptoms among psychiatric patients. In this naturalistic prospective study, 149 patients with affective, anxiety, substance use, and other disorders were interviewed shortly after entering treatment, which included psychotherapy, pharmacotherapy, or both. Follow-up interviews were conducted 6 and 12 months later. Attachment styles, DSM-III-R PDs, and symptoms were assessed using structured interviews and consensus ratings. At intake, borderline, avoidant, and dependent PD features correlated consistently with symptom severity and secure attachment correlated inversely with two of four symptom scales. Secure attachment was linked with greater relative improvement in global functioning and a more benign course of anxiety symptoms over 6 months. Borderline PD features predicted less relative improvement of depressive symptoms over 6 months. These findings clarify the relations between attachment styles and PD features and they point to potential mediators of treatment response.

Determination of the binding specificity of an integral membrane protein by saturation transfer difference NMR: RGD peptide ligands binding to integrin alphaIIbbeta3

Saturation transfer difference (STD) NMR is a fast and versatile method to screen compound mixtures in the presence of a receptor for binding affinity and to characterize the ligand's binding epitope. Here we demonstrate that ligand interactions with integral membrane proteins can be investigated by STD NMR if the receptor is embedded into the lipid bilayer of a liposome. The integrin alphaIIbbeta3, also termed GPIIb-IIIa, is a platelet surface glycoprotein that plays a pivotal role in platelet aggregation and that interacts with proteins and peptides presenting the peptide recognition motif RGD. Purified human integrin alphaIIbbeta3 was incorporated into liposomes, and the binding of RGD peptides was analyzed by STD NMR techniques. Cyclo(RGDfV) gave STD NMR effects in the presence of liposomes containing the integrin. The magnitude of the STD effect as a function of the ligand's concentration gave a value for the dissociation constant of 30-60 microM. Adding the weakly binding RGD to the solution of cyclo(RGDfV) resulted in STD effects of the stronger ligand cyclo(RGDfV) only. This demonstrates in agreement with literature that the peptide RGD is a much weaker ligand to the integrin than the peptide cyclo(RGDfV) that largely replaces the RGD peptides from the binding site. The binding epitope of the ligand cyclo(RGDfV) was characterized by STD NMR to contain sections of the D-Phe, the Val methyl groups, Arg alpha, beta, and gamma protons, one Hbeta of Asp, and one Halpha of Gly.

Surgery for upper cervical spine instabilities in children

BACKGROUND

Due to the paucity of existing data with regard to surgical fusion of upper cervical spine instabilities in the paediatric population, we feel encouraged to report the results of our own series to provide additional information to the available body of literature.

METHODS

Since 1991 N = 11 children underwent a total of N = 13 surgical procedures for N = 8 posttraumatic, N = 2 congenital and N = 1 postinfectious instabilities at a mean age of 10 years (range: 3-16 years). Transoral odontectomies, ventral odontoid screw-fixations, dorsal wiring or -clamping and transarticular screw-fixations were performed for stabilization and iliac crest bone graft used for fusion. Pain scores, neurological status and radiological results were documented at regular intervals (mean follow-up: 25.4 months).

RESULTS

Stable fusion was achieved in all patients as documented on flexion/extension films and tomographies. At the latest follow-up N = 2 patients had improved and N = 9 were equal to their preoperative neurological status. Pain scores were improved in N = 9 patients. N = 2 children developed "bystander-fusion" after C0/2 wiring. N = 3 peri-operative complications occurred as transient neurological deteriorations. In one case this resulted from the resection of a lower brainstem tumour prior to the stabilization procedure. One was attributed to sublaminar wiring in the case of an os odontoideum and one occurred due to slippage of the halo orthosis after transoral odontectomy before definitive dorsal stabilization was carried out.

INTERPRETATION

In accordance with the recent literature, we argue for the application of modern screw fixations and treatment algorithms as established for adults in upper cervical spine instabilities of older children. Techniques and indications remain problematic for those younger than 6 years and may have to be individualized in congenital instabilities.

Merkel cell carcinoma: a rare cause of hypervascular nasal tumor

Cutaneous neuroendocrine carcinoma, first described in 1972, is an aggressive disease usually occurring in sun-exposed skin. Other sites have been described, however; such tumors occasionally occur within the nasal fossa. A high rate of metastasis (>30%) explains the poor prognosis. Descriptions of the imaging features of these tumors, mainly located in cutaneous region, are rare. We therefore present the imaging features of two cases of Merkel cell carcinoma involving the sinonasal region, suggestive of a hypervascular tumor.

Is stagnating flow in former feeding arteries an indication of cerebral hypoperfusion after resection of arteriovenous malformations?

OBJECT

The authors' goal in this study was to challenge the proposed mechanism of the occlusive hyperemia theory, in which it is asserted that stagnating flow in the former feeding arteries of cerebral arteriovenous malformations (AVMs) leads to parenchymal hypoperfusion or ischemia, from which postoperative edema and hemorrhage originate.

METHODS

Cortical oxygen saturation (SaO2) was measured in 52 patients by using microspectrophotometry in areas adjacent to AVMs before and after resection. The appearance of the former feeding arteries was categorized as normal (Group A); moderately stagnating (Group B); and excessively stagnating (Group C) on postoperative angiographic fast-film series. Patients and SaO2 values were pooled accordingly and compared using analysis of variance and Duncan tests (p < 0.05). Angiographic stagnation times in former feeding arteries were correlated in a linear regression/correlation analysis with SaO2 data (p < 0.05). All values are given as the mean +/- standard deviation. The average median postoperative SaO2 in Group C (15 patients) was significantly higher than in Groups B (17 patients) and A (20 patients) (Group C, 75.2 +/- 8.5; Group B, 67.5 +/- 10.8; Group A, 67.1 +/- 12 %SaO2), as was the average postoperative increase in SaO2 (Group C. 25.9 +/- 14.9; Group B, 14.6 +/- 14; Group A, 11.1 +/- 14 %SaO2). Angiographically confirmed stagnation times were also significantly longer in Group C than in Group B (Group C, 5.6 +/- 2.5; Group B, 1.3 +/- 0.6 seconds). A significant correlation/regression analysis showed a clear trend toward higher postoperative SaO2 levels with increasing stagnation time.

CONCLUSIONS

Stagnating flow in former feeding arteries does not cause cortical ischemia, but its presence on angiographic studies is usually indicative of hyperperfusion in the surrounding brain tissue after AVM resection. In the context of the pathophysiology of AVMs extrapolations made from angiographically visible shunt flow to blood flow in the surrounding brain tissue must be regarded with caution.

Group epitope mapping by saturation transfer difference NMR to identify segments of a ligand in direct contact with a protein receptor

A protocol based on saturation transfer difference (STD) NMR spectra was developed to characterize the binding interactions at an atom level, termed group epitope mapping (GEM). As an example we chose the well-studied system of galactose binding to the 120-kDa lectin Ricinus communis agglutinin I (RCA(120)). As ligands we used methyl beta-D-galactoside and a biantennary decasaccharide. Analysis of the saturation transfer effects of methyl beta-D-galactoside showed that the H2, H3, and H4 protons are saturated to the highest degree, giving evidence of their close proximity to protons of the RCA(120) lectin. The direct interaction of the lectin with this region of the galactose is in excellent agreement with results obtained from the analysis of the binding specificities of many chemically modified galactose derivatives (Bhattacharyya, L.; Brewer, C. F. Eur. J. Biochem. 1988, 176, 207-212). This new NMR technique can identify the binding epitope of even complex ligands very quickly, which is a great improvement over time-consuming chemical modifications. Efficient GEM benefits from a relatively high off rate of the ligand and a large excess of the ligand over the receptor. Even for a ligand like the biantennary decasaccharide with micromolar binding affinity, the binding epitopes could easily be mapped to the terminal beta-D-Gal-(1-4)-beta-D-GlcNAc (beta-D-GlcNAc = N-acetyl-D-glucosamine) residues located at the nonreducing end of the two carbohydrate chains. The binding contribution of the terminal galactose residue is stronger than those of the penultimate GlcNAc residues. We could show that the GlcNAc residues bind "edge-on" with the region from H2 to H4, making contact with the protein. Analysis of STD NMR experiments performed under competitive conditions proved that the two saccharides studied bind at the same receptor site, thereby ruling out unspecific binding.

Effect of nasal dilators on pleasantness, intensity and sampling behaviors of foods in the oral cavity

The present study assessed the effect of nasal dilators on ratings of food intensity and pleasantness. Participants wearing the dilators rated foods in the oral cavity as less pleasant and more intense than did those participants wearing a placebo strip. In addition, they consumed less of the test stimuli. Significant interactions were noted between food stimuli and placebo vs. nasal dilator strip conditions, indicating certain food qualities, particularly initial pleasantness, combine to produce enhanced changes in perception. Changes in the intensity and pleasantness of foods was most pronounced in foods characterized as initially pleasant. A review of studies to date indicate that both foods and odors are perceived as more intense and less pleasant during nasal dilation, suggesting an impact of the dilators on both retronasal and orthonasal air flow.

[Inner ear and subarachnoid spaces: relations and diseases]

The purpose of this article is to describe, with 5 clinical cases, the physiological communications between the inner ear and the subarachnoid spaces (SAS) and present the imaging features with regard to. Therefore we briefly illustrate abnormal communications between SAS and perilymphatic fluids in certain cochlear and internal acoustic meatus (IAM) malformations and their consequences. Imaging features may depict diffusion pathway of bacterial meningitis to membranous labyrinth via the cochlear aqueduct or via the IAM. Rarely, in some patients referred for cochleovestibular symptoms, imaging features may display skull base tumors involving the area of cochlear or vestibular aqueduct aperture. Therefore, in patients referred for cochleovestibular symptoms, MR and CT study should carefully scrutinise not only the IAM but also the aperture of the cochlear and the vestibular aqueducts and the cerebellopontine meninges.

Postoperative complications in otospongiosis: usefulness of MR imaging

BACKGROUND AND PURPOSE

Sensorineural hearing loss (SNHL) is a rare complication of stapes surgery that may arise for many reasons. Usually, the pathogenesis of SNHL can be established by clinical and CT examinations. The purpose of this study was to evaluate the utility of MR imaging when CT findings are normal or not contributive.

METHODS

Eleven patients with SNHL (in some instances, associated with vertigo) after stapedectomy, in whom CT showed no well-defined cause, were examined by MR imaging.

RESULTS

MR studies established the additional findings of reparative intravestibular granuloma (n = 2), intralabyrinthine hemorrhage (n = 1), and bacterial labyrinthitis (n = 1). In five cases, MR findings were similar to CT findings. In two cases, CT and MR results were normal. Revision surgery was performed in five patients and confirmed the MR findings in each case.

CONCLUSION

If CT is not contributive as to the origin of SNHL and vertigo occurring after stapes surgery, then MR imaging may be helpful in these patients.