Effects of radiation on a model of malignant glioma invasion

We sought to characterize the effects of radiation alone and in combination with BCNU and dexamethasone on malignant glioma invasion. A model of malignant glioma invasion into a gel matrix of collagen type I was used to characterize response to radiation treatment for four malignant glioma cell lines (C6, U251, U373, A172) and nine primary human glioblastoma explants. A radiation dose dependent inhibition of invasion was noted for the C6 astrocytoma cell line but not the other cell lines or explants. Addition of BCNU and dexamethasone to radiation produced additional inhibition of invasion among the cell lines and explants but could not suppress invasion entirely.

The effects of pregnancy and smooth muscle contractility on cervical distensibility in the rat

OBJECTIVE

We sought to compare distensibility of the isolated rat cervix from nonpregnant rats (n = 6), rats at midgestation (n = 5), and rats at term gestation (n = 4).

STUDY DESIGN

The cervix was excised, and one cervical channel was cannulated from both ends and positioned in the organ chamber for perfusion-superfusion by a peristaltic pump at an intraluminal pressure of 30 mm Hg for 30 minutes. After the equilibration period, perfusion was stopped, the outlet was closed, and the cervix was inflated with a syringe pump. The volume was increased at a rate of 3.33 microL/s until intraluminal pressure reached approximately 120 mm Hg. The outlet was then opened, and the cervix was perfused at 30 mm Hg of intraluminal pressure for another 30 minutes. The volume-pressure relationships were obtained 3 times without any agent present and in the presence of 60-mmol/L potassium chloride or 10(-4)-mol/L 3-morpholinosydnonimine hydrochloride (also known as SIN-1).

RESULTS

The volume-pressure relationship was shifted to the right during progression of pregnancy, demonstrating increased compliance of the cervix. The nonspecific depolarizing agent potassium chloride or the nitric oxide donor 3-morpholinosydnonimine did not affect volume-pressure relationships in cervices from nonpregnant rats, rats at midgestation, or rats at term gestation.

CONCLUSION

The volume-pressure relationship in the isolated cannulated rat cervix reflects the resistance of the organ to increased intraluminal pressure. The compliance of the cervix is increased as pregnancy progresses, demonstrating decreased resistance to stretch. Activation or inhibition of cervical smooth muscle does not contribute to the physical properties of the cervix, which controls compliance-resistance.

Graft-versus-host-disease-associated thymic damage results in the appearance of T cell clones with anti-host reactivity

BACKGROUND

We studied whether T-cell clones, which appear in the periphery as a result of the failure of thymic negative selection during graft-versus-host disease (GVHD), have any in vivo anti-host reactivity and can cause GVHD in an adoptive transfer model.

METHODS

We performed our studies in a murine model (B10.BR into CBA/J) for allogeneic bone marrow transplantation with major histocompatibility complex-matched and minor histocompatibility antigen-mismatched unrelated donors and unique Vbeta T-cell deletion patterns in donors and recipients.

RESULTS

GVHD resulted in the appearance of Vbeta6+ T cells as a result of a loss of negative selection. We found that Vbeta6+ T cells from normal donors proliferated in vitro and in vivo. Depletion of Vbeta6+ T cells from the donor T-cell inoculum resulted in less GVHD morbidity and a decrease in the loss of thymic cellularity. To test the anti-host reactivity of de novo generated Vbeta6+ T cells in animals with GVHD, we developed an adoptive transfer model of splenic T cells from CBA/J host animals with GVHD into sublethally irradiated CBA/J recipients Depletion of Vbeta6+ T cells from the splenic T cells before adoptive transfer could significantly decrease the transient GVHD morbidity in the sublethally irradiated hosts.

CONCLUSIONS

Our data indicate that GVHD-associated thymic damage results in a loss of thymic negative selection, which leads to the appearance of T-cell clones with anti-host reactivity in vitro and in vivo.

Fas-deficient lpr mice are more susceptible to graft-versus-host disease

The Fas/Fas ligand (FasL) pathway is involved in a variety of regulatory mechanisms that could be important for the development of graft-vs-host disease (GVHD) after bone marrow transplantation (BMT), such as cytolysis of target cells by cytotoxic T cells, regulation of inflammatory responses, peripheral deletion of autoimmune cells, costimulation of T cells, and activation-induced cell death. To further evaluate the role of Fas/FasL in the complex pathophysiology of GVHD, we used Fas-deficient B6.lpr mice as recipients in a MHC-matched minor histocompatibility Ag-mismatched murine model for GVHD after allogeneic BMT (C3H.SW-->B6). We found a significantly higher morbidity and mortality from GVHD compared with control B6 recipients. In contrast, B6.lpr recipients had very little hepatic GVHD, although all other specific GVHD target organs (skin, intestines, and thymus) were more severely affected than in the control B6 recipients. B6.lpr recipients with GVHD demonstrated intact donor lymphoid engraftment and an increase in expansion of donor T cells and monocytes/macrophages compared with control B6 recipients. Serum levels of IFN-gamma and TNF-alpha were higher in B6.lpr recipients than in control B6 recipients, and monocytes/macrophages in B6.lpr recipients appeared more sensitized. B6.lpr recipients had more residual peritoneal macrophages after BMT, and peritoneal macrophages from B6.lpr mice could induce a greater proliferative response from C3H.SW splenocytes. This study demonstrates that the expression of Fas in the recipient is required for GVHD of the liver, but shows unexpected consequences when host tissues lack the expression of Fas for the development of GVHD in other organs and systemic GVHD.

Brain insulin receptors and spatial memory. Correlated changes in gene expression, tyrosine phosphorylation, and signaling molecules in the hippocampus of water maze trained rats

Evidence accumulated from clinical and basic research has indirectly implicated the insulin receptor (IR) in brain cognitive functions, including learning and memory (Wickelgren, I. (1998) Science 280, 517-519). The present study investigates correlative changes in IR expression, phosphorylation, and associated signaling molecules in the rat hippocampus following water maze training. Although the distribution of IR protein matched that of IR mRNA in most forebrain regions, a dissociation of the IR mRNA and protein expression patterns was found in the cerebellar cortex. After training, IR mRNA in the CA1 and dentate gyrus of the hippocampus was up-regulated, and there was increased accumulation of IR protein in the hippocampal crude synaptic membrane fraction. In the CA1 pyramidal neurons, changes in the distribution pattern of IR in particular cellular compartments, such as the nucleus and dendritic regions, was observed only in trained animals. Although IR showed a low level of in vivo tyrosine phosphorylation, an insulin-stimulated increase of in vitro Tyr phosphorylation of IR was detected in trained animals, suggesting that learning may induce IR functional changes, such as enhanced receptor sensitivity. Furthermore, a training-induced co-immunoprecipitation of IR with Shc-66 was detected, along with changes in in vivo Tyr phosphorylation of Shc and mitogen-activated protein kinase, as well as accumulation of Shc-66, Shc-52, and Grb-2 in hippocampal synaptic membrane fractions following training. These findings suggest that IR may participate in memory processing through activation of its receptor Tyr kinase activity, and they suggest possible engagement of Shc/Grb-2/Ras/mitogen-activated protein kinase cascades.

Characterization and radiation resistance of new isolates of Rubrobacter radiotolerans and Rubrobacter xylanophilus

In this study we characterized new strains of the slightly thermophilic species Rubrobacter radiotolerans and the thermophilic species Rubrobacter xylanophilus, both of which were previously represented only by the type strains isolated, respectively, from Japan and the United Kingdom. The new isolates were recovered from two hot springs in central Portugal after gamma irradiation of water and biofilm samples. We assessed biochemical characteristics, performed DNA-DNA hybridization, and carried out 16S rDNA sequence analysis to demonstrate that the new Rubrobacter isolates belong to the species R. radiotolerans and R. xylanophilus. We also show for the first time that the strains of R. xylanophilus and other strains of R. radiotolerans are extremely gamma radiation resistant.

The measurement of expressed emotion in relationships between staff and service users: the use of short speech samples

OBJECTIVES

Research on expressed emotion (EE) has demonstrated a remarkable consistency across cultures and over time; the psychosocial climate in relationships is important in determining the course of problems in mental health. The rating of EE might be described as the least accessible aspect of this literature to those who have not undertaken a training course. The purpose of this study was twofold: first, to obtain EE ratings for staff-patient relationships via interview and speech sample methods, in order to estimate the validity of the shorter method (the Five-Minute-Speech-Sample, FMSS); second, to examine the generalizability of the FMSS rating method to raters who were not previously trained to rate EE.

DESIGN AND METHOD

Staff (N = 15) working in a day hospital service for people with enduring mental health problems were interviewed about their work with at least one patient (N = 32), and also asked to provide an FMSS on each relationship. Ratings of FMSS-EE were subsequently compared with the Camberwell Family Interview-EE ratings. Following an hour-long training period, the FMSS-EE ratings of five postgraduate students were then compared with those of a criterion rater.

RESULTS

Correspondence between the two measures of EE was found to be good, with overall agreement achieved in 89.7% of cases. Raters with very limited training in the concept and rating of EE were accurate in identifying the overall rating of the relationship in question, but less accurate in identifying specific critical comments.

CONCLUSION

The FMSS technique can be used reliably to identify negative relationships even by raters given very limited training. Clinical and research applications are suggested.

Artefact on MRA following aneurysm clipping: an in vitro study and prospective comparison with conventional angiography

Using both an experimental model and clinical cases, we looked at the artefact produced by Aesculap titanium-alloy aneurysm clips on MRA. Experimentally, the volume affected by artefact was 50 % less when the clip was imaged lying parallel to the main ferromagnetic field than when lying perpendicular to it. Clinically, MRA was prospectively compared with digital subtraction angiography (DSA) in nine patients who had undergone aneurysm clipping. One patient with a non-diagnostic MRA due to movement artefact was excluded. In all other cases there was an area of signal loss surrounding the clips, obscuring the immediately adjacent vessel segments. There was good demonstration of the adjacent bifurcations in five cases and the contralateral circulation was seen well in all patients. In three cases in which the adjacent bifurcations were not seen, considerable vasospasm was suggested by MRA and confirmed with DSA. In one patient an unclipped contralateral ophthalmic artery aneurysm was identified using both modalities. In this series there were no adverse events relating to clips in either static or time-varying magnetic fields.

Effects of radiation on a three-dimensional model of malignant glioma invasion

An experimental model of malignant glioma growth involving implantation of spheroids into a gel matrix of collagen type I has been developed. This model has been used to characterize changes in glioma cell invasion in response to single dose and fractionated radiation treatment. Suspensions of C6 astrocytoma cells were grown in spinner culture flasks to yield spheroids of varying size (300-1000 microm). Implantation of spheroids into a gel matrix of collagen type I was associated with measurable invasion of the surrounding gel by individual tumor cells. Changes in the distance of invasion in response to single dose and fractionated radiation were measured. Changes in apoptosis and proliferative indices in different regions of the spheroids in response to radiation were also assessed. In unirradiated gels, maximum depth of invasion, 1300-1750 microm, was achieved by 5 days after implantation. A radiation dose-dependent inhibition of invasion was noted and was most profound for larger spheroids. Fractionation of the radiation dose was associated with a partial recovery of invasion. Changes in apoptotic and proliferative indices in response to radiation depended on the region of the spheroid examined. Increases in apoptosis were noted for cells at the surface of the spheroid and invading cells while cells at the centre of the spheroid demonstrated virtually no increase in apoptosis. Likewise, a dose-dependent decrease in proliferative indices following radiation was noted among the invading cells and cells at the surface of the spheroid but not at the centre of the spheroid. We have described a model of malignant glioma invasion which possesses many of the qualities of in vivo malignant gliomas. Within this model, invasion appeared to be inhibited by radiation in a dose- and fractionation-dependent fashion. Measurement of apoptotic and cell proliferation indices favour a direct cytotoxic effect on the invading cells as the most likely mechanism for this phenomenon.

Quality control for functional magnetic resonance imaging using automated data analysis and Shewhart charting

A data acquisition and analysis protocol for quality control (QC) of functional magnetic resonance imaging studies is presented. Two sets of data are acquired, single-timepoint data for measurement of signal-to-ghost and signal-to-noise ratios, and multiple-timepoint data for measurement of short-term drift. Since manual data analysis can be time consuming and an impediment to regular QC, an automated data processing scheme is presented. The use of automated Shewhart charting is proposed to identify significant changes in each parameter over the long term. The protocol has successfully identified system faults and deteriorations undetected by conventional QC.

Systemic sclerosis (scleroderma) in two iron ore mines

Six males with systemic sclerosis were observed in the work forces of two iron ore mines. The usual spectrum of clinical features encountered in systemic sclerosis patients were present. Histologic examination of pulmonary tissue was performed on three of the cases and showed features of both silicosis and scleroderma but to different degrees and stages of development. Exposure to high levels of silica-containing dusts had occurred in all six cases.

Widespread chromosomal abnormalities in high-grade ductal carcinoma in situ of the breast. Comparative genomic hybridization study of pure high-grade DCIS

For a variety of technical reasons it is rarely possible to study cytogenetic abnormalities in ductal carcinoma in situ (DCIS) using traditional techniques. However, by combining molecular biology and computerized image analysis it is possible to carry out cytogenetic analyses on formalin-fixed, paraffin-embedded tissue, using comparative genomic hybridization (CGH). The purpose of this study was to identify the prevalence of chromosomal amplifications and deletions in high-grade DCIS and to look specifically for unique or consistent abnormalities in this pre-invasive cancer. Twenty-three cases of asymptomatic, non-palpable, screen-detected, high-grade DCIS were examined using CGH on tumour cells obtained from histology slides. All cases showed chromosomal abnormalities. A wide variety of amplifications and deletions were spread across the genome. The most frequent changes were gains of chromosomes 17 (13 of 23), 16p (13 of 23), and 20q (9 of 23) and amplifications of 11q13 (22 of 23), 12q 24.1-24.2 (12 of 23), 6p21.3 (11 of 23), and 1q31-qter (6 of 23). The most frequent deletions were on 13q 21.3-q33 (7 of 23), 9p21 (4 of 23), and 6q16.1 (4 of 23). These findings indicate that high-grade DCIS is, from a cytogenetic viewpoint, an advanced lesion. There was no absolutely consistent finding in every case, but amplification of 11q13 was found in 22 of the 23 cases. The precise significance of this is unknown at present. This region of chromosome 11q harbours a number of known oncogenes, including cyclin D1 andINT2. It is likely that many of these findings are the result of accumulated chromosomal abnormalities, reflecting an unstable genome in established malignancy.

3-nitroadipate, a metabolic intermediate for mineralization of 2, 4-dinitrophenol by a new strain of a Rhodococcus species

The bacterial strain RB1 has been isolated by enrichment cultivation with 2,4-dinitrophenol as the sole nitrogen, carbon, and energy source and characterized, on the basis of 16S rRNA gene sequence comparison, as a Rhodococcus species closely related to Rhodococcus opacus. Rhodococcus sp. strain RB1 degrades 2,4-dinitrophenol, releasing the two nitro groups from the compound as nitrite. The release of nitro groups from 2,4-dinitrophenol occurs in two steps. First, the 2-nitro group is removed as nitrite, with the production of an aliphatic nitro compound identified by 1H nuclear magnetic resonance and mass spectrometry as 3-nitroadipate. Then, this metabolic derivative is further metabolized, releasing its nitro group as nitrite. Full nitrite assimilation upon reduction to ammonia requires that an additional carbon source be supplied to the medium.

A comparison of calcaneus ultrasound and dual X-ray absorptiometry in healthy North American youths and young adults

Quantitative ultrasound is the newest noninvasive method to be accepted for assessing bone mineral in adults. Heel ultrasound measurements correlate with bone density measurements by dual X-ray absorptiometry (DXA) and predict fracture risk in adults. Far less is known about the value of calcaneus ultrasound (CUS) in children. We determine spine, femoral neck, and whole-body bone mineral by DXA and heel bone mass by CUS in 125 youths (69 females, 56 males) ages 9-25 yr. CUS and DXA measurements of bone mass increased with age and pubertal development during adolescence in a parallel fashion. Among females, Tanner stage was a stronger predictor than age for all CUS and DXA measurements, and among males, pubertal stage was a stronger predictor for spine bone mineral apparent density (BMAD) and femoral bone mineral density (BMD). CUS measurements correlated moderately well with DXA measurements of the spine, femoral neck, and whole-body BMD and spine BMAD (r = 0.23-0.58, p < 0. 008). CUS warrants further study as a tool for assessing bone mineral acquisition in children.

Quantitative detection of Sphingomonas chlorophenolica in soil via competitive polymerase chain reaction

The 16S ribosomal RNA gene sequence of the pentachlorophenol degrader Sphingomonas chlorophenolica strain RA2 was used to generate specific polymerase chain reaction (PCR) primers for the detection of this strain in soil, whereas a region internal to the two primers was used to provide an S. chlorophenolica strain RA2-specific oligonucleotide probe. The PCR detection system resulted in a 727 bp product detectable via gel electrophoresis and hybridization. It was specific for strain RA2 and its close relative, S. chlorophenolica ATCC 39723, as evidenced by PCR amplifications of a range of bacterial genomic DNAs. Tests of total microbial community DNA obtained from five uninoculated and two RA2-inoculated soils confirmed this specificity for introduced S. chlorophenolica RA2. Strain RA2 could be detected in soil down to a level of 10(3) cfu g-1 soil. Two strategies were followed to generate internal standard DNA for competitive PCR. First, a 479 bp MIMICS fragment was obtained based on a previously constructed gene cassette; however, this standard did not reliably quantify RA2 targets. Low stringency PCR performed with a range of bacterial genomic DNAs resulted in the generation of an amplicon with a Paenibacillus azotofixans strain that was slightly smaller than the RA2-derived product. Both products were easily separable via conventional gel electrophoresis. The use of this competitor in a threefold dilution scheme applied to the target DNA allowed for the quantitative detection of RA2-specific target DNA molecules from pure culture and from soil. The fate of strain RA2 in pentachlorophenol-contaminated soil was described using this competitive PCR approach, and the organism was shown to persist at two inoculum levels over prolonged periods of time.

Gastrostomy buttons for nutritional support on chronic dialysis

RATIONALE

Nutritional support for children on chronic dialysis often involves the use of nasogastric tubes or gastrostomy feeding. We report our experience using gastrostomy buttons (GB) over a 6.6-year period to document their success/failure, the feeding regimens employed and the impact on growth.

DESIGN

In 339 patient months of prospective observation, 22 children (14 male) commenced gastrostomy feeding at a median age of 2.3 years (range 0.2-10.3 years). Sixteen patients had an initial gastrostomy catheter inserted at the same time as a chronic dialysis catheter. Eighteen patients were established on continuous cycling peritoneal dialysis (CCPD) and four on haemodialysis (HD).

RESULTS

The mean duration of combined gastrostomy feeding and chronic dialysis was 14.5 months (range 2.4 56 months). In 20 of the children followed for 6 months on combined GB feeding and dialysis, the mean protein and energy intakes were 2.5 g/kg bodyweight/day (range 1.7-3.4 g) and 108 kcal/kg bodyweight/day (range 72-129 kcal). The mean energy intake achieved was 116% (range 98-155%) of the estimated average requirement (EAR) for energy. The mean percentage of total energy and protein intakes delivered via the GB during the study period was 61% (33-95%) and 61% (23-98%) respectively. Mean height standard deviation score (SDS) was -2.22 prior to GB feeding and -2.06 at the end of the study period (P = 0.005) and mean weight SDS was -2.22 and -1.16 (P = 0.001) respectively. The mean life of the GB was 7.7 months (range 2.6 14 months) with most button changes due to leakage problems. Two episodes of peritonitis were attributable to the GB with one requiring peritoneal dialysis catheter removal due to candida infection. The GB was removed at a mean of 2.8 months (range 0.8-8.3 months) after renal transplantation in 13 children.

CONCLUSION

The gastrostomy button provides a valuable and aesthetically appealing route for nutritional support with few complications.

Evidence for genetic linkage to alcohol dependence on chromosomes 4 and 11 from an autosome-wide scan in an American Indian population

To identify specific genes affecting vulnerability or resistance, we performed a whole-autosomal genome scan for genetic linkage to alcohol dependence in a Southwestern American Indian tribe. Genotypes at 517 autosomal microsatellite loci and clinical evaluations were available for 152 subjects belonging to extended pedigrees and forming 172 sib-pairs. Highly suggestive evidence for linkage emerged for two genomic regions using two- and multipoint sib-pair regression methods; both regions harbored neurogenetic candidate genes. The best evidence is seen with D11S1984 (nominal P = 0.00007, lod approximately equal to 3.1) on chromosome 11p, in close proximity to the DRD4 dopamine receptor and tyrosine hydroxylase (TH) genes. Good evidence is seen with D4S3242 (nominal P = 0.0002, lod approximately equal to 2.8) on chromosome 4p, near the beta1 GABA receptor gene. Interestingly, three loci in the alcohol dehydrogenase gene cluster on chromosome 4q showed evidence for linkage with two-point analyses, but not multipoint analysis.