Radiotherapy in the Maxillary Hemangioma

We present the case of a large maxillary hemangioma treated by radiotherapy. Only 4 cases managed by radiotherapy have been reported in the literature, and most authors negate the radiosensitivity of the tumor. In our patient, the outcome was excellent; by 6 months tumor reduction was more than 50%. This is the first case referred to in the literature whose radiotherapy response was evaluated by magnetic resonance imaging. We describe the clinical and imaging findings of this very rare tumor and its evolution. We also comment on the literature reviewed.

Binding of Insecticidal Crystal Proteins of Bacillus thuringiensis to the Midgut Brush Border of the Cabbage Looper, Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae), and Selection for Resistance to One of the Crystal Proteins

The susceptibility of Trichoplusia ni larvae to several Bacillus thuringiensis insecticidal crystal proteins (ICPs) was tested. Neonatal larvae proved to be susceptible to solubilized trypsin-treated CryIA(a), CryIA(b), and CryIA(c) (50% lethal concentrations [LC(50)s], 570, 480, and 320 ng/cm, respectively) but showed little susceptibility to CryIB and CryID (LC(50)s, 5,640 and 2,530 ng/cm, respectively). The toxicity of ICPs was correlated to binding to the epithelial brush border of the midgut, as revealed by immunocytochemical staining with monoclonal antibodies. In vitro binding experiments with iodinated ICPs and brush border membrane vesicles indicated that CryIA(b) and CryIA(c) share the same high-affinity binding site, whereas CryIA(a) binds to a different one. The affinities of CryIA(b) and CryIA(c) for the binding site were similar (K(d) = 3.6 and 4.7 nM, respectively), and the mean binding-site concentration was 0.71 pmol/mg of vesicle protein. Selection of a population with increasing concentrations of CryIA(b) produced 31-fold resistance in seven generations. The realized heritability (h) was 0.19. The increase of homozygosity (for resistance factors) as selection proceeded was reflected in the increase in the slopes of the dose-mortality curves. Resistance was specific for CryIA(b) and did not extend to CryIA(a) or even to CryIA(c). This result was not predicted by the binding-site model, in which CryIA(b) and CryIA(c) bind to the same high-affinity binding site. This result may suggest a more complicated relationship between in vitro binding of ICPs to specific sites in the epithelial membrane of the midgut and the in vivo toxic effect.

A Change in a Single Midgut Receptor in the Diamondback Moth (Plutella xylostella) Is Only in Part Responsible for Field Resistance to Bacillus thuringiensis subsp. kurstaki and B. thuringiensis subsp. aizawai

A population (SERD3) of the diamondback moth (Plutella xylostella L.) with field-evolved resistance to Bacillus thuringiensis subsp. kurstaki HD-1 (Dipel) and B. thuringiensis subsp. aizawai (Florbac) was collected. Laboratory-based selection of two subpopulations of SERD3 with B. thuringiensis subsp. kurstaki (Btk-Sel) or B. thuringiensis subsp. aizawai (Bta-Sel) increased resistance to the selecting agent with little apparent cross-resistance. This result suggested the presence of independent resistance mechanisms. Reversal of resistance to B. thuringiensis subsp. kurstaki and B. thuringiensis subsp. aizawai was observed in the unselected SERD3 subpopulation. Binding to midgut brush border membrane vesicles was examined for insecticidal crystal proteins specific to B. thuringiensis subsp. kurstaki (Cry1Ac), B. thuringiensis subsp. aizawai (Cry1Ca), or both (Cry1Aa and Cry1Ab). In the unselected SERD3 subpopulation (ca. 50- and 30-fold resistance to B. thuringiensis subsp. kurstaki and B. thuringiensis subsp. aizawai), specific binding of Cry1Aa, Cry1Ac, and Cry1Ca was similar to that for a susceptible population (ROTH), but binding of Cry1Ab was minimal. The Btk-Sel (ca. 600-and 60-fold resistance to B. thuringiensis subsp. kurstaki and B. thuringiensis subsp. aizawai) and Bta-Sel (ca. 80-and 300-fold resistance to B. thuringiensis subsp. kurstaki and B. thuringiensis subsp. aizawai) subpopulations also showed reduced binding to Cry1Ab. Binding of Cry1Ca was not affected in the Bta-Sel subpopulation. The results suggest that reduced binding of Cry1Ab can partly explain resistance to B. thuringiensis subsp. kurstaki and B. thuringiensis subsp. aizawai. However, the binding of Cry1Aa, Cry1Ac, and Cry1Ca and the lack of cross-resistance between the Btk-Sel and Bta-Sel subpopulations also suggest that additional resistance mechanisms are present.

Salivary scintigraphy for assessing the protective effect of pilocarpine in head and neck irradiated tumours

Patients with head and neck cancers can develop salivary hypofunction after radiotherapy. The use of pilocarpine during radiotherapy treatment has been shown to be an effective treatment, although its usefulness is being discussed. The aim of this study was: (1) to determine the value of a semiquantitative scintigraphy method for measuring the uptake and excretory salivary function of patients with head and neck irradiated tumours; and (2) to study the usefulness of pilocarpine as a salivary gland protector during radiotherapy. We prospectively studied 49 patients (mean age 61 years, range 29-87 years) with head and neck cancer in need of radiotherapy. Patients were divided into two groups consecutively: group P (26 patients) received 5 mg of pilocarpine three times per day starting the day before radiation therapy, and group NP (23 patients) received radiotherapy without pilocarpine and were used as the control group. Salivary gland scintigraphy and a visual analogue scale (VAS) of mouth dryness were obtained from each patient before radiotherapy and during the first year after treatment. The most frequent finding after radiotherapy was a quick impairment in parotid and submaxillary excretion (P < 0.001). There were no statistical differences comparing the pilocarpine group against the non-pilocarpine group. Parotid and submaxillary uptake significantly decreased after radiotherapy in both groups (P < 0.001). However, a tendency to recover within the pilocarpine group was observed in both the parotids and the submaxillary glands at 12 months. No differences were found comparing the VAS results in both groups. Strikingly, VAS data did not correlate with salivary gland dysfunction observed by means of scintigraphy. In conclusion, salivary scintigraphy is a useful technique to evaluate objectively the salivary gland function of patients with head and neck irradiated tumours as well as to test the response to pilocarpine. However, despite better results on the salivary uptake at 12 months, pilocarpine did not significantly improve salivary gland function.

Identification and characterization of the new bacillus thuringiensis serovars pirenaica (serotype H57) and iberica (serotype H59)

Two new Bacillus thuringiensis strains have been classified by the H antigen of the cells and differentiated by their morphological, biochemical and molecular characteristics. The flagellar agglutination showed that both strains bore specific H antigens which allowed their classification as the new serotypes H57 and H59. The serovar names proposed for the type strains characterized in this work are B. thuringiensis ser. pirenaica, for the H serotype 57, and B. thuringiensis ser. iberica, for the H serotype 59. Further characterization of these strains, by means of SDS-PAGE, Western inmunodetection, plasmid profile and cry-gene identification by polymerase chain reaction, confirmed the originality of the two novel serotypes. Toxicity tests carried out against several insect species, belonging to the orders Lepidoptera, Diptera and Coleoptera, showed no detectable insecticidal activity for either of the B. thuringiensis strains.

Real-size CT slices to optimize brachytherapy in the plastic tube technique for oral cavity neoplasms

To optimize brachytherapy treatments in the plastic tube technique and to have a quality assurance system, we use Real-Size CT slices (RSCTS). This procedure permits us to have a more precise knowledge of the dose distribution in the tumor and in the healthy neighboring tissues.

Granulocyte macrophage-colony-stimulating factor mouthwashes heal oral ulcers during head and neck radiotherapy

PURPOSE

To evaluate the effectiveness of granulocyte macrophage-colony-stimulating factor GM-CSF mouthwashes in the epithelization of radiation-induced oral mucosal ulceration, control of pain, and weight loss.

METHODS AND MATERIALS

Twelve patients received curative radiotherapy for head and neck carcinoma. All had oropharyngeal and/or oral mucosa irradiation, with a median dose of 72 Gy (range 50-74), with conventional fractionation. A total of 300 microg of GM-CSF in 250 cc of water for 1 h of mouthwashing was prescribed. The procedure started once oral ulceration in the irradiation field was detected. Patients, examined twice a week, were evaluated for oral ulceration, pain, and weight loss. Blood tests were taken weekly during GM-CSF administration. A comparison was carried out with 12 retrospective case-matched controls.

RESULTS

In the GM-CSF group, mucosa ulcerations healed in 9 of 12 (75%) of the patients during the course of the radiotherapy. Fifty percent of the patients said they felt less pain during the GM-CSF treatment; 30% needed morphine. The mean and median weight loss as a percentage of baseline weight in addition to the actual weight were 4.2% and 3%, respectively (variation ranged between a gain of 1% and a loss of 13%). No GM-CSF-related side effects were found. In the case control group, in the 12 cases, oral ulcerations increased during radiotherapy and two patients needed intubation intake and hospital admission, as opposed to the GM-CSF group. The mean and median percentage of weight loss were 5.8% and 5%, respectively. Sixty percent of patients needed morphine, as opposed to 30% in the GM-CSF group.

CONCLUSIONS

Granulocyte macrophage-colony-stimulating factor was effective in curing mucosal ulcerations during the course of radiotherapy. This is the first time we have seen a drug with this capacity. Although the GM-CSF seems to be effective in the control of pain, oral intake, and weight loss, we need further studies with a greater number of patients to confirm our premise. Double-blind trials are necessary for future research into the control of pain and weight loss.

Planar patterned magnetic media obtained by ion irradiation

By ion irradiation through a lithographically made resist mask, the magnetic properties of cobalt-platinum simple sandwiches and multilayers were patterned without affecting their roughness and optical properties. This was demonstrated on arrays of 1-micrometer lines by near- and far-field magnetooptical microscopy. The coercive force and magnetic anisotropy of the irradiated regions can be accurately controlled by the irradiation fluence. If combined with high-resolution lithography, this technique holds promise for ultrahigh-density magnetic recording applications.

Mismatch negativity in the neurophysiologic/behavioral evaluation of auditory processing deficits: a case study

The subject of this case report is an 18-year-old woman with grossly abnormal auditory brain stem response (ABR), normal peripheral hearing, and specific behavioral auditory processing deficits. Auditory middle latency responses (MLRs) and cortical potentials N1, P2, and P300 were intact. The mismatch negativity (MMN) was normal in response to certain synthesized speech stimuli and impaired to others--consistent with her behavioral discrimination of these stimuli. Behavioral tests of auditory processing were consistent with auditory brain stem dysfunction. A neuropsychological evaluation revealed normal intellectual and academic performance. The subject was in her first year of college at the time of the evaluation. This case study is important because: (1) Although there have been several reports of absent/abnormal ABR with preserved peripheral hearing and deficits in auditory processing, little is known about the specific nature of the auditory deficits experienced by these individuals. Such information may be valuable to the clinical management of patients with this constellation of findings. (2) Of interest is the information that the mismatch negativity (MMN) cortical event-related potential can bring to the evaluation of patients with auditory processing deficits. The MMN reflects central auditory processing of small acoustic differences and may provide an objective measure of auditory discrimination. (3) From a theorectical standpoint, a patient with neural deficits affecting specific components of the auditory pathway provides insight into the relationship between evoked potentials and physiological mechanisms of auditory processing. How do various components of the auditory pathway contribute to speech discrimination? How might evoked potentials reflect the processes underlying the neural coding of specific features of speech stimuli such as timing and spectral cues?

Broad-spectrum resistance to Bacillus thuringiensis toxins in Heliothis virescens

Evolution of pest resistance to insecticidal proteins produced by Bacillus thuringiensis (Bt) would decrease our ability to control agricultural pests with genetically engineered crops designed to express genes coding for these proteins. Previous genetic and biochemical analyses of insect strains with resistance to Bt toxins indicate that (i) resistance is restricted to single groups of related Bt toxins, (ii) decreased toxin sensitivity is associated with changes in Bt-toxin binding to sites in brush-border membrane vesicles of the larval midgut, and (iii) resistance is inherited as a partially or fully recessive trait. If these three characteristics were common to all resistant insects, specific crop-variety deployment strategies could significantly diminish problems associated with resistance in field populations of pests. We present data on Bt-toxin resistance in Heliothis virescens, a major agricultural pest targeted for control with Bt-toxin-producing crops. A laboratory strain of H. virescens developed resistance in response to selection with the Bt toxin CryIA(c). In contrast to other cases of Bt-toxin resistance, this H. virescens strain exhibits cross-resistance to Bt toxins that differ significantly in structure and activity. Furthermore, the resistance in this strain is not accompanied by significant changes in toxin binding, and resistance is inherited as an additive trait when larvae are treated with high doses of CryIA(c) toxin. These findings have important implications for Bt-toxin-based pest control.

[Postoperative infection in cesarean section. Comparative study according to the antibiotic used at 2 maternity hospitals in the Central African Republic]

Puerperal infection is not specifically a complication seen in Africa, and the risk of infection in Europe in general, and especially in France, is not negligible. The authors report their experience, which is broad on this subject.

Repetitive recycling of guanosine triphosphate cyclohydrolase I for synthesis of dihydroneopterin triphosphate

A procedure for enzymatic production of dihydroneopterin triphosphate is described that allows GTP cyclohydrolase I to be reused repetitively. The reaction takes place in an ultrafiltration cell, and the product is collected in the filtrate, whereas the enzyme remains in the cell to be reused with additional substrate. This is repeated until the enzyme activity drops below a desirable level. The purity of the dihydroneopterin triphosphate is satisfactory for utilization of this compound for studies on enzymes involved in the synthesis of tetrahydrobiopterin and drosopterin. A procedure for purification of dihydroneopterin triphosphate is described that uses C18-silica and silica cartridges.

Sepiapterin reductase in human amniotic and skin fibroblasts, chorionic villi, and various blood fractions

Sepiapterin reductase activity has been measured in amniotic fibroblasts by two procedures: one photometric and the other HPLC-fluorimetric. Both can be used for quantitative measurements, but the latter has considerable advantages including smaller standard deviation, much lower detection limit, and less volume of sample required. Sepiapterin reductase activity was also assayed in skin fibroblasts, chorionic villi and various blood fractions including stimulated mononuclear blood cells. Red blood cells have a low specific activity compared to unstimulated mononuclear blood cells, although the latter have a mean value with a high standard deviation. When the mononuclear blood cells were cultured for 5 days, the mean specific activity increased and the range became tighter. Enzyme stability and N-acetylserotonin inhibition were also studied.

Purification of guanosine triphosphate cyclohydrolase I from Escherichia coli. The use of competitive inhibitors versus substrate as ligands in affinity chromatography

Different affinity chromatography ligands have been compared for the purification of guanosine triphosphate (GTP) cyclohydrolase I, an enzyme that catalyses the transformation of GTP into formate and dihydroneopterin triphosphate, the first metabolite in the biosynthetic pathway of the pterins. When this enzyme is purified by affinity chromatography on GTP-Sepharose a major fraction of the activity is lost and the yield of enzyme decreases as the amount of enzyme applied to the column decreases. The use of nucleotide competitive inhibitors (UTP and ATP) as ligands in the affinity column has shown that the extent of inactivation of the enzyme is related to the affinity of the enzyme for the ligand. Further, the extent of inactivation was reduced by reducing the length of the columns when using the same volume of GTP-Sepharose. Dihydrofolate-Sepharose gave consistently higher yields of GTP cyclohydrolase I regardless of the amount of enzyme applied, but several other proteins were also obtained. For a high purification of GTP cyclohydrolase I the best yield may be obtained with UTP as the affinity ligand and with the shortest length possible of the affinity column, and the purity of enzyme is comparable with that obtained with GTP-Sepharose.

Formation of beta,gamma-methylene-7,8-dihydroneopterin 3'-triphosphate from beta,gamma-methyleneguanosine 5'-triphosphate by GTP cyclohydrolase I of Escherichia coli

GTP cyclohydrolase I of Escherichia coli converts [beta,gamma-methylene] GTP to a fluorescent product that is characterized as [beta,gamma-methylene]dihydroneopterin triphosphate. Interaction between the GTP analog and the enzyme gave a Ki of 3.0 microM, which may be compared to the Km of 0.1 microM for GTP. This new analog of dihydroneopterin triphosphate may, in turn, be converted to the same greenish-yellow pteridines (compounds X, X1, and X2) that are obtained from dihydroneopterin triphosphate. Because of its stability to phosphatase action, this analog may be useful for studies in pteridine metabolism.

Lymphovenous shunting in a case of retroperitoneal seminoma

Lymphovenous shunting in a patient presenting with a metastatic retroperitoneal seminoma is reported. Its aetiology as well as the prognostic value are discussed. A search of the literature has been made and the various theories offered to explain such a phenomonen have been evaluated, in an attempt to corelate them with the findings in our case.