Volumetric evaluation of an alternative bladder point in brachytherapy for locally advanced cervical cancer.

PURPOSE: To evaluate an alternative dose point, so-called ALG (for Alain Gerbaulet), for the bladder in comparison to the International Commission on Radiation Units and Measurements (ICRU) point and D2cm(3) (minimal dose to maximally exposed 2 cm(3)) in a large cohort of patients with locally advanced cervical cancer treated with external beam radiotherapy followed by image-guided pulsed dose rate brachytherapy. METHODS AND MATERIALS: For each patient, the ALG point was constructed 1.5 cm above the ICRU bladder, parallel to the tandem (coronal and sagittal planes). The dosimetric data from 162 patients were reviewed. RESULTS: Average doses to ALG and bladder points were 19.40 Gy ± 7.93 and 17.14 ± 8.70, respectively (p=0.01). The 2 cm(3) bladder dose averaged 24.40 ± 6.77 Gy. Ratios between D2cm(3) and dose points were 1.37 ± 0.46 and 1.68 ± 0.74 (p<0.001) for ALG and ICRU points, respectively. Both dose points appeared correlated with D2cm(3) (p<0.001) with coefficients of determination (R(2)) of 0.331 and 0.399 respectively. The estimated dose to the ICRU point of the rectum was 12.77 ± 4.21 and 15.76 ± 5.94 for D2cm(3) (p<0.0001). Both values were significantly correlated (p<0.0001, R(2) = 0.485). CONCLUSION: The ALG point underestimates the D2cm(3), but its mean on a large cohort is closer to D2cm(3) than the dose to ICRU point. However, it shows great variability between cases and the weak strength of its correlation to D2cm(3) indicates that it is not a good surrogate for individual volumetric evaluation of the dose D2cm(3).

[Locally advanced cervical cancer: Should intensity-modulated radiotherapy replace brachytherapy?]. / Complément d'irradiation dans le cancer du col de l'utérus localement évolué : curiethérapie utérovaginale ou radiothérapie conformationnelle avec modulation d'intensité ?

Intensity-modulated conformal radiotherapy (IMRT) is booming as treatment of locally advanced cervical cancer. This technique reduces the doses delivered to organs at risk and, by analogy to the irradiation of prostate cancer, opens the door to the possibility of dose escalation to levels close or similar to those achieved by brachytherapy. To date, several studies comparing IMRT with brachytherapy have been published, often methodologically flawed, concluding sometimes that both techniques are comparable. These results should be taken with extreme caution and should not overshadow the recent advances in brachytherapy with the use of 3D imaging and optimization. Preliminary works also showed that the combination of 3D optimized brachytherapy with IMRT could improve the management of the local disease especially for lesions poorly covered by intracavitary techniques.

Developmental regulation of neural cell adhesion molecule in human prefrontal cortex.

Neural cell adhesion molecule (NCAM) is a membrane-bound cell recognition molecule that exerts important functions in normal neurodevelopment including cell migration, neurite outgrowth, axon fasciculation, and synaptic plasticity. Alternative splicing of NCAM mRNA generates three main protein isoforms: NCAM-180, -140, and -120. Ectodomain shedding of NCAM isoforms can produce an extracellular 105-115 kilodalton soluble neural cell adhesion molecule fragment (NCAM-EC) and a smaller intracellular cytoplasmic fragment (NCAM-IC). NCAM also undergoes a unique post-translational modification in brain by the addition of polysialic acid (PSA)-NCAM. Interestingly, both PSA-NCAM and NCAM-EC have been implicated in the pathophysiology of schizophrenia. The developmental expression patterns of the main NCAM isoforms and PSA-NCAM have been described in rodent brain, but no studies have examined NCAM expression across human cortical development. Western blotting was used to quantify NCAM in human postmortem prefrontal cortex in 42 individuals ranging in age from mid-gestation to early adulthood. Each NCAM isoform (NCAM-180, -140, and -120), post-translational modification (PSA-NCAM) and cleavage fragment (NCAM-EC and NCAM-IC) demonstrated developmental regulation in frontal cortex. NCAM-180, -140, and -120, as well as PSA-NCAM, and NCAM-IC all showed strong developmental regulation during fetal and early postnatal ages, consistent with their identified roles in axon growth and plasticity. NCAM-EC demonstrated a more gradual increase from the early postnatal period to reach a plateau by early adolescence, potentially implicating involvement in later developmental processes. In summary, this study implicates the major NCAM isoforms, PSA-NCAM and proteolytically cleaved NCAM in pre- and postnatal development of the human prefrontal cortex. These data provide new insights on human cortical development and also provide a basis for how altered NCAM signaling during specific developmental intervals could affect synaptic connectivity and circuit formation, and thereby contribute to neurodevelopmental disorders.

Inhibition of epidermal growth factor receptor signalling reduces hypercalcaemia induced by human lung squamous-cell carcinoma in athymic mice.

The purpose of this study was to evaluate the role of the epidermal growth factor receptor (EGFR) in parathyroid hormone-related protein (PTHrP) expression and humoral hypercalcaemia of malignancy (HHM), using two different human squamous-cell carcinoma (SCC) xenograft models. A randomised controlled study in which nude mice with RWGT2 and HARA xenografts received either placebo or gefitinib 200 mg kg(-1) for 3 days after developing HHM. Effectiveness of therapy was evaluated by measuring plasma calcium and PTHrP, urine cyclic AMP/creatinine ratios, and tumour volumes. The study end point was at 78 h. The lung SCC lines, RWGT2 and HARA, expressed high levels of PTHrP mRNA as well as abundant EGFR protein, but very little erbB2 or erbB3. Both lines expressed high transcript levels for the EGFR ligand, amphiregulin (AREG), as well as, substantially lower levels of transforming growth factor-alpha (TGF-alpha), and heparin binding-epidermal growth factor (HB-EGF) mRNA. Parathyroid hormone-related protein gene expression in both lines was reduced 40-80% after treatment with 1 muM of EGFR tyrosine kinase inhibitor PD153035 and precipitating antibodies to AREG. Gefitinib treatment of hypercalcaemic mice with RWGT2 and HARA xenografts resulted in a significant reduction of plasma total calcium concentrations by 78 h. Autocrine AREG stimulated the EGFR and increased PTHrP gene expression in the RWGT2 and HARA lung SCC lines. Inhibition of the EGFR pathway in two human SCC models of HHM by an anilinoquinazoline demonstrated that the EGFR tyrosine kinase is a potential target for antihypercalcaemic therapy.

Dual-porosity expanded polytetrafluoroethylene implants for lip, nasolabial groove, and melolabial groove augmentation.

OBJECTIVE: To evaluate the clinical outcomes with the use of a dual-porosity expanded polytetrafluoroethylene implant for midfacial rejuvenation. DESIGN: An institutional review board-approved retrospective chart review was conducted of all patients who underwent implantation with the dual-porosity expanded polytetrafluoroethylene implant between 2001 and 2005. RESULTS: A total of 170 patients, with 612 implants, were evaluated. Only 8 patients had minor complications, 3 of which necessitated implant removal. The overall results of independent observer analysis of outcomes were favorable in the majority of cases. CONCLUSION: The dual-porosity expanded polytetrafluoroethylene implant is safe and reliable to use for midfacial implantation.

Mechanisms of thorium migration in a semiarid soil.

Thorium concentrations at Kirtland Air Force Base training sites in Albuquerque, NM, have been previously described; however, the mechanisms of thorium migration were not fully understood. This work describes the processes affecting thorium mobility in this semiarid soil, which has implications for future remedial action. Aqueous extraction and filtration experiments have demonstrated the colloidal nature of thorium in the soil, due in part to the low solubility of thorium oxide. Colloidal material was defined as that removed by a 0.22-microm or smaller filter after being filtered to nominally dissolved size (0.45 microm). Additionally, association of thorium with natural organic matter is suggested by micro- and ultrafiltration methods, and electrokinetic data, which indicate thorium migration as a negatively charged particle or anionic complex with organic matter. Soil fractionation and digestion experiments show a bimodal distribution of thorium in the largest and smallest size fractions, most likely associated with detrital plant material and inorganic oxide particles, respectively. Plant uptake studies suggest this could also be a mode of thorium migration as plants grown in thorium-containing soil had a higher thorium concentration than those in control soils. Soil erosion laboratory experiments with wind and surface water overflow were performed to determine bulk soil material movement as a possible mechanism of mobility. Information from these experiments is being used to determine viable soil stabilization techniques at the site to maintain a usable training facility with minimal environmental impact.

Elevated prolactin levels in patients with schizophrenia: mechanisms and related adverse effects.

The neurologic processes involved in schizophrenia are complex and diverse and the mechanisms through which antipsychotic agents exert their effects have been only partly elucidated. Hyperprolactinemia is a common side effect of treatment with many antipsychotics and is particularly associated with conventional ('typical') agents as well as the atypical antipsychotic risperidone. In contrast, other atypical agents introduced over the last decade do not elevate prolactin levels. This article discusses the regulatory mechanisms involved in prolactin secretion, the physiologic role of prolactin, and the etiology of hyperprolactinemia. Elevated prolactin levels may play important roles, both direct and indirect, in various pathologic states, including breast cancer, osteoporosis, cardiovascular disorders, and sexual disturbances. Antipsychotic-induced hyperprolactinemia may be associated with similar clinical manifestations; these are examined with particular reference to patients with schizophrenia.

Cytokine effects on cortical neuron MAP-2 immunoreactivity: implications for schizophrenia.

BACKGROUND: Cytokines demonstrate diverse actions in the brain and modulate systemic and central nervous system (CNS) responses to injury, infection, and inflammation. Cytokines in the CNS are elevated during infection and ischemia, two neurodevelopmental insults associated with increased schizophrenia risk. We hypothesize that cytokine-mediated neuronal injury during development may contribute to schizophrenia pathophysiology, causing subtle alterations in neuronal number and density. METHODS: We examined cytokine regulation of neuronal number in embryonic day 18 rat cortical cultures using MAP-2 immunohistochemistry. Mixed cultures derived from frontal cortex were fixed and stained after 48-hour exposure to the proinflammatory interleukin-1beta (IL-1beta), interleukin-6 (IL-6), or tumor necrosis factor-alpha (TNF-alpha; 0, 10, 100, or 1000 units/mL). RESULTS: IL-1beta (maximum effect 35%) and IL-6 (maximum effect 29%) produced dose-dependent decreases in the number of cells (neurons) immunoreactive for MAP-2 antibody, suggesting decreased neuronal survival. TNF-alpha also tended to decrease MAP-2 immunostaining at the highest dose tested. CONCLUSIONS: Our data suggest a role for cytokines in the modulation of neuronal survival during neurodevelopment, a finding potentially relevant to schizophrenia pathophysiology. If cytokine-mediated neuronal injury proves to be a common response to gestational insults associated with increased schizophrenia risk, the pharmacologic modulation of these molecules may have clinical utility.

Identification of a 43-kDa protein in human liver cytosol that binds to the 3'-untranslated region of CYP2A6 mRNA.

Hepatic expression of cytochrome P450 2A6 (CYP2A6) varies widely in humans and is induced during hepatitis; however, the mechanism regulating CYP2A6 has not been established. The murine orthologue Cyp2a5 is regulated post-transcriptionally by mRNA stabilization. A 43-kDa protein that binds to the 3'-untranslated region (3'-UTR) of Cyp2a5 mRNA has been identified, but its role in mRNA stabilization is unclear. We hypothesized that similar interactions occur between cytosolic proteins in human liver and CYP2A6 3'-UTR mRNA. We identified, by RNA electrophoretic mobility shift assay, an hepatic cytosolic protein that binds specifically to sequences in the 3'-UTR of CYP2A6. Complexes did not form with denatured proteins and were eliminated with proteinase K digestion. Complex formation was inhibited with a molar excess of unlabeled CYP2A6 RNA but not by non-specific competitor RNA. Protein-mRNA interactions were not affected by probe denaturation, suggesting that RNA secondary structure is not essential for binding. UV cross-linking of complexes revealed RNA-binding proteins in both human and mouse liver cytosols with molecular masses of approximately 43 kDa. Using truncated RNA probes corresponding to various lengths of CYP2A6 mRNA, the protein-binding site was localized to a 50-nucleotide region between bases 1478 and 1527 of the 3'-UTR. Complex formation with hepatic cytosolic protein from four human subjects correlated with levels of hepatic CYP2A6 microsomal protein, suggesting a possible regulatory role. Further characterization of the RNA-binding protein, the primary binding site, and the influence of this interaction on CYP2A6 mRNA stability will help to elucidate the relevance of these findings to the post-transcriptional control of CYP2A6.

Prenatal exposure to maternal infection alters cytokine expression in the placenta, amniotic fluid, and fetal brain.

Prenatal exposure to infection appears to increase the risk of schizophrenia and other neurodevelopmental disorders. We have hypothesized that cytokines, generated in response to maternal infection, play a key mechanistic role in this association. E16 timed pregnancy rats were injected i.p. with Escherichia coli lipopolysaccharide (LPS) to model prenatal exposure to infection. Placenta, amniotic fluid and fetal brains were collected 2 and 8h after LPS exposure. There was a significant treatment effect of low-dose (0.5mg/kg) LPS on placenta cytokine levels, with significant increases of interleukin (IL)-1beta (P<0.0001), IL-6 (P<0.0001), and tumor necrosis factor-alpha (TNF-alpha) (P=0.0001) over the 2 and 8h time course. In amniotic fluid, there was a significant effect of treatment on IL-6 levels (P=0.0006). Two hours after maternal administration of high-dose (2.5mg/kg) LPS, there were significant elevations of placenta IL-6 (P<0.0001), TNF-alpha (P<0.0001), a significant increase of TNF-alpha in amniotic fluid (P=0.008), and a small but significant decrease in TNF-alpha (P=0.035) in fetal brain. Maternal exposure to infection alters pro-inflammatory cytokine levels in the fetal environment, which may have a significant impact on the developing brain.

Cortical bcl-2 protein expression and apoptotic regulation in schizophrenia.

BACKGROUND: The etiology of schizophrenia remains unknown; however, a role for apoptosis has been hypothesized. Bcl-2 is a potent inhibitor of apoptosis and also exerts neurotrophic activity in the central nervous system (CNS). Bcl-2 expression is increased in the CNS of several neurodegenerative disorders. Given that schizophrenia has certain features of a limited neurodegenerative disorder, it was hypothesized that cortical Bcl-2 expression is increased in schizophrenia. METHODS: Postmortem temporal cortex was obtained from the Stanley Foundation Neuropathology Consortium with matched control, schizophrenic, bipolar, and depressed subjects. Bcl-2 protein was measured by enzyme-linked immunoassay (ELISA) and Western blot. Primary analysis was limited to schizophrenia versus control subjects. RESULTS: The ELISA demonstrated 25% less Bcl-2 protein in schizophrenia (p =.046), supported by Western blot results. A secondary analysis of schizophrenic and bipolar subjects revealed twofold higher mean Bcl-2 in antipsychotic-treated versus neuroleptic-naive subjects. CONCLUSIONS: Contrary to our hypothesis, cortical Bcl-2 was reduced in schizophrenia. This supports the notion that schizophrenia is not a classic neurodegenerative disorder; however, less Bcl-2 protein may signal neuronal vulnerability to proapoptotic stimuli and to neuronal atrophy. Also, the association between neuroleptic exposure and higher Bcl-2 levels could underlie the favorable long-term outcomes of patients who receive maintenance antipsychotic treatment.

Neurosteroid modulation of embryonic neuronal survival in vitro following anoxia.

Neurosteroids are synthesized de novo in the brain from cholesterol or peripheral steroid precursors and modulate inhibitory gamma-aminobutyric acid (GABA(A)) and excitatory N-methyl-D-aspartate (NMDA) receptors. Evidence indicates that neurosteroids are neuroprotective and important during neurodevelopment. We tested the hypothesis that neurosteroids increase embryonic neuronal survival following anoxia in rat embryonic day 18 cerebral cortical cultures to examine potential neurosteroid modulation of this insult during early development. Twenty-four hours after plating in serum-free medium, cultures were exposed to DHEA, DHEAS, or allopregnanolone (10(-10), 10(-8), or 10(-6) M), or vehicle, for 24 h (n=9 per treatment condition). Cultures were then subjected to anoxia for 2 h and subsequently reincubated for 24 h prior to neuron immunostaining with microtubule-associated protein 2 (MAP-2) antibody. Supernatant from DHEA and DHEAS-exposed cultures was tested for 17beta-estradiol metabolite formation by radioimmunoassay. DHEA 10(-6) and 10(-8) M significantly increased neuron survival by 85-87% following anoxia. DHEAS 10(-6) M significantly increased neuron survival by 74% following anoxia, but DHEAS 10(-10) M decreased neuron survival after this insult. Allopregnanolone had modest effects on neuron survival that did not attain statistical significance. 17beta-Estradiol concentrations were below the limit of detection in all specimens tested (sensitivity 4.7 nM). Our data indicate that pretreatment with DHEA and DHEAS at physiologically relevant concentrations promotes neuronal survival following anoxia in embryonic rat cerebral cortical cultures, and that these effects are not secondary to 17beta-estradiol metabolite formation. DHEA and DHEAS modulation of anoxia in embryonic neurons may be relevant to disorders of neurodevelopment involving this insult.

An evaluation of hospital cleaning regimes and standards.

A four-part study assessing cleanliness in up to 113 environmental surfaces in an operating theatre and a hospital ward is reported. Surfaces were assessed visually, using microbiological methods and ATP bioluminescence. Results from a preliminary random survey indicated variability in cleanliness. These results were then used to select sites for monitoring before and after routine cleaning, over a 14-day period. Using published microbiological and ATP specifications 70 and 76% of these sites were unacceptable after cleaning. Visual assessment was a poor indicator of cleaning efficacy with only 18% considered unacceptable. Sites most likely to fail in the ward were in the toilet and kitchen, areas which are frequently implicated in the spread of infectious intestinal disease. Operating theatre sites had lower ATP results but 61% of sites would be considered unacceptable. There was no significant difference in general microbiological or ATP results overall before and after routine cleaning. Although some important hand contact sites showed no significant difference, overall there was a significant decrease in staphylococcal and enterobacteria counts in the ward but not in the operating theatre after cleaning. The routine cleaning programmes used did not include a biocide and cleaning using a hypochlorite based sanitizer gave much lower values. The results are discussed in relation to infection control, cleaning audits and cleaning schedules: an integrated cleaning monitoring programme using ATP bioluminescence in conjunction with visual and microbiological assessments is recommended.

Olanzapine increases allopregnanolone in the rat cerebral cortex.

BACKGROUND: The neurosteroid allopregnanolone (3alpha-hydroxy-5alpha-pregnan-20-one) has anxiolytic and anticonvulsant properties, potentiating GABA(A) receptor chloride channel function with 20-fold higher potency than benzodiazepines. Behavioral studies demonstrate that olanzapine has anxiolyticlike properties in animals, but the mechanism responsible for these effects is not clear. We examined the effect of acute olanzapine administration on cerebral cortical allopregnanolone and its relationship to serum progesterone and corticosterone levels in rats. METHODS: Male Sprague-Dawley rats were habituated to intraperitoneal (IP) saline injection for 5 days. On the day of the experiment, rats were injected with olanzapine (0, 2.5, 5.0, or 10.0 mg/kg IP, 10-11 rats per condition). Rats were sacrificed 1 hour later, and cerebral cortical allopregnanolone levels and serum progesterone and corticosterone levels were measured by radioimmunoassay. RESULTS: Olanzapine increases cerebral cortical allopregnanolone up to fourfold, depending on dose. Positive correlations were observed between cerebral cortical allopregnanolone and serum progesterone levels and between cerebral cortical allopregnanolone and serum corticosterone levels. CONCLUSIONS: Olanzapine-induced increases in the potent GABA(A) receptor modulator allopregnanolone may alter GABAergic neurotransmission, possibly contributing to antipsychotic efficacy. If allopregnanolone alterations are linked to psychotic symptom relief, neurosteroids may represent molecules for pharmacologic intervention.

Developmental expression of Bcl-2 protein in human cortex.

Apoptosis is essential for normal human neurodevelopment and is increasingly recognized for its role in various neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Bcl-2 is a 26 kDa membrane-associated protein known to protect neurons against apoptosis. Interestingly, Bcl-2 protein levels are altered in certain neurodegenerative disorders that reveal increased apoptosis. However, little is known about the normal expression of Bcl-2 protein in human brain. Bcl-2 protein levels were determined by ELISA and semiquantitative Western Blotting in the frontal cortex of 20 human post-mortem brains, separated into three groups: six infants (age: 0.83+/-1.0 years, mean+/-S.D.), five adolescents (age: 17.4+/-1.7 years), and nine adults (age: 41.0+/-9.6 years). All subjects died of non-CNS related illness and had no history of psychiatric illness. Bcl-2 increased significantly across the age groups in the ELISA (p=0.0058) and the Western Blot (p=0.002) experiments. The ELISA demonstrated significant differences in Bcl-2 levels between infant and adolescent cortex (p<0.05), and between infant and adult cortex (p<0.01) using a post-hoc Tukey's multiple comparison test. The Western blots demonstrated a similar significant increase in Bcl-2 between infant and adult cortex (p<0. 01). A secondary analysis showed significant correlation between individual ages and Bcl-2 levels (r(2)=0.4933, p=0.0006). This study demonstrates that Bcl-2 protein expression in human cortex is developmentally regulated and supports the hypothesis that Bcl-2 is involved in normal aging.

Effects of Percoll separation, cryoprotective agents, and temperature on plasma membrane permeability characteristics of murine spermatozoa and their relevance to cryopreservation.

Cryopreservation of murine spermatozoa would provide an efficient method for preserving important genotypes. However, to date such methods have resulted in low survivals with significant variability. To address this issue, a series of five experiments was performed to determine the cryobiological characteristics of murine spermatozoa. Experiments 1 and 2 investigated the effect of Percoll separation on the hydraulic conductivity (L(p)) of murine spermatozoa. Both Percoll separation and cryoprotective agents (CPAs) decreased the L(p). However, these effects were not additive. Experiment 3 was performed to determine the effect of temperature on L(p) in the presence of cryoprotectants (L(p)(CPA)), cryoprotectant permeability (P(CPA)), and the reflection coefficient (sigma) in spermatozoa from both ICR and B6C3F1 mice. Permeability parameters decreased as temperature decreased, and permeability characteristics differed between strains. In experiments 4 and 5, theoretical simulations for CPA addition and removal were developed and empirically tested. Strain-specific methods for CPA addition and removal based upon the fundamental cryobiological characteristics of murine spermatozoa resulted in higher survivals than current methods or procedures, which were used as controls.

Body mass index and health.

OBJECTIVES: This article describes the prevalence of the four international body mass index (BMI) categories--underweight (18.5 or less), acceptable weight (18.6 to 24.9), overweight (25 to 29.9) and obese (30 or more)--by selected socio-demographic and lifestyle characteristics. It also examines the association between BMI and selected health problems. DATA SOURCE: The data are from the household component of the 1996/97 National Population Health Survey, conducted by Statistics Canada. Results are based on a sample of 50,347 respondents aged 20 to 64. ANALYTICAL TECHNIQUES: Prevalence estimates of BMI categories were calculated. Multivariate analyses were used to examine associations between BMI and various health conditions by smoking status, while controlling for age and sex. MAIN RESULTS: In 1996/97, about half of Canadian adults were in the acceptable weight range; 34% were overweight; 12%, obese; and 2%, underweight. Being overweight or obese was associated with asthma, arthritis, back problems, high blood pressure, diabetes and thyroid disorders, although this varied with smoking status. Underweight smokers had high odds of reporting cancer, bowel disorders, ulcers, and migraine.

Trends in medicinal chemistry.

On December 3, 1998, the Society for Medicines Research held a meeting entitled Trends in Medicinal Chemistry at the National Heart and Lung Institute, London. The meeting was conceived to alert researchers to compounds in early development or new discoveries likely to lead to new approaches to disease treatment in the near future. Presentations covered potential therapies for CNS disorders, through immune disease and cancer to cardiovascular diseases. Specific new discoveries described at the meeting included the antipsychotic agent ORG-23366; the anticonvulsants SB-204269, SB-258229 and SB-270664; the tyrosine kinase inhibitors CT-5269 and CT-4694; VEGF inhibitors from Zeneca; the elastase inhibitor GW-311616A; a serine protease inhibitor from Roche; the MMPI D-2163; two antimigraine follow-ons to rizatriptan, L-775606 and L-785103; the P(2T) inhibitor AR-C69931MX and a follow-on compound; and the PDE5 inhibitor sildenafil.