Differences in children's sound production when speaking with a cochlear implant turned on and turned off

Twenty children who have worn a Cochlear Corporation cochlear implant for an average of 33.6 months participated in a device-on/off experiment. They spoke 14 monosyllabic words three times each after having not worn their cochlear implant speech processors for several hours. They then spoke the same speech sample again with their cochlear implants turned on. The utterances were phonetically transcribed by speech-language pathologists. On average, no difference between speaking conditions on indices of vowel height, vowel place, initial consonant place, initial consonant voicing, or final consonant voicing was found. Comparisons based on a narrow transcription of the speech samples revealed no difference between the two speaking conditions. Children who were more intelligible were no more likely to show a degradation in their speech production in the device-off condition than children who were less intelligible. In the device-on condition, children sometimes nasalized their vowels and inappropriately aspirated their consonants. Their tendency to nasalize vowels and aspirate initial consonants might reflect an attempt to increase proprioceptive feedback, which would provide them with a greater awareness of their speaking behavior.

Phase I trial and tumour localisation of the anti-EGFR monoclonal antibody ICR62 in head and neck or lung cancer

The purpose of this study was to determine the effect of the first rat monoclonal antibody (MAb ICR62) to the epidermal growth factor receptor (EGFR) in a phase I clinical trial in patients with unresectable squamous cell carcinomas. This antibody effectively blocks the binding of EGF, transforming growth factor (TGF)-alpha and HB-EGF to the EGFR, inhibits the growth in vitro of tumour cell lines which overexpress the EGFR and eradicates such tumours when grown as xenografts in athymic mice. Eleven patients with squamous cell carcinoma of the head and neck and nine patients with squamous cell carcinoma of the lung, whose tumours expressed EGFR, were recruited. Groups of three patients were treated with 2.5 mg, 10 mg, 20 mg or 40 mg of ICR62 and a further eight patients received 100 mg. All patients were evaluated for toxicity using WHO criteria. Patients' sera were tested for the clearance of MAb ICR62 and the development of human anti-rat antibodies (HARA). No serious (WHO Grade III-IV) toxicity was observed in patients treated with up to 100 mg of antibody ICR62. Antibody ICR62 could be detected at 4 h and 24 h in the sera of patients treated with 40 mg or 100 mg of ICR62. Only 4/20 patients showed HARA responses (one at 20 mg, one at 40 mg and two at 100 mg doses) and of these only the former two were anti-idiotypic responses. In four patients receiving doses of ICR62 at 40 mg or greater, biopsies were obtained from metastatic lesions 24 h later and examined for the localisation of ICR62 using anti-rat antibody reagent. In these patients we showed the localisation of MAb ICR62 to the membranes of tumour cells; this appeared to be more prominent at the higher dose of 100 mg. On the basis of these data we conclude that MAb ICR62 can be administered safely to patients with squamous cell carcinomas and that it can localise efficiently to metastases even at relatively low doses.

Effect of context and adjuvant on the immunogenicity of recombinant proteins and peptide conjugates derived from the polymorphic malarial surface antigen MSA2

We have identified a 51 kDa glycosylated myristylated merozoite surface antigen (MSA2) as the target of a number of monoclonal antibodies which inhibit in vitro invasion of the human malarial parasite Plasmodium falciparum. This antigen has been shown to exist in a limited number of strain specific forms but despite wide variation in the sequences of the internal repeat regions both N and C terminal elements of the protein are almost totally conserved. Accordingly, we prepared a large number of overlapping peptide constructs and demonstrated that one peptide SNTFINNA (E71) from the N terminus and two peptides, QHGHMHGS (G5) and NTSDSQKE (G12) from the C terminus could, when suitably conjoined to the carrier protein diphtheria toxoid (DT), elicit antibodies reactive with MSA2 from diverse strains of P. falciparum. Here we compare the immunogenicity of these peptide constructs with two recombinant proteins containing the entire amino acid sequence of MSA2 from the FCQ-27/PNG strain (1609) and the 3D7 strain (1623). We have formulated these recombinant and peptide antigens with Freund's adjuvant, Alum and Algammulin. Both recombinant and peptide antigens elicit high titre antibodies when tested by ELISA against the immunogens themselves. Although both recombinant proteins include the constant region peptide sequences E71, G5 and G12, the extent of ELISA cross reaction between antibody raised against recombinant and peptide antigen or antibody raised against peptide and recombinant antigen is small and sporadic, and depends to an extent on the adjuvant employed. Antisera against both recombinant proteins 1609 and 1623 detected either recombinant on Western blots, as well as detecting native MSA2 in whole protein extracts from both FCQ-27/PNG and 3D7 strains. Antisera against peptide construct E71 recognized recombinant 1609 but not 1623 but recognized the native MSA2 in both strains studied. Antisera against peptide construct G5 showed a similar pattern of recognition but also detected recombinant 1623 on Western blotting. These results emphasize the importance of context and adjuvant on the ability of selected immunogenic epitopes to elicit antibodies appropriately directed against the native antigen.

Relationships between speech production and speech perception skills in young cochlear-implant users

The purpose of this investigation was to examine the relationships between young cochlear-implant users' abilities to produce the speech features of nasality, voicing, duration, frication, and place of articulation and their abilities to utilize the features in three different perceptual conditions: audition-only, vision-only, and audition-plus-vision. Subjects were 23 prelingually deafened children who had at least 2 years of experience with a Cochlear Corporation Nucleus cochlear implant, and an average of 34 months. They completed both the production and perception version of the Children's Audio--visual Feature Test, which is comprised of ten consonant--vowel syllables. An information transmission analysis performed on the confusion matrices revealed that children produced the place of articulation fairly accurately and voicing, duration, and frication less accurately. Acoustic analysis indicated that voiced sounds were not distinguished from unvoiced sounds on the basis of voice onset time or syllabic duration. Subjects who were more likely to produce the place feature correctly were likely to have worn their cochlear implants for a greater length of time. Pearson correlations revealed that subjects who were most likely to hear the place of articulation, nasality, and voicing features in an audition-only condition were also most likely to speak these features correctly. Comparisons of test results collected longitudinally also revealed improvements in production of the features, probably as a result of cochlear-implant experience and/or maturation.

Acquisition of speech by children who have prolonged cochlear implant experience

The four purposes of this investigation were to assess whether children acquire intelligible speech following prolonged cochlear-implant experience and examine their speech error patterns, to examine how age at implantation influences speech acquisition, to assess how speech production and speech perception skills relate, and to determine whether cochlear implant recipients who formerly used simultaneous communication (speech and manually coded English) begin to use speech without sign to communicate. Twenty-eight prelinguistically deafened children who use a Nucleus cochlear implant were assigned to one of three age groups, according to age at implantation: 2-5 yrs (N = 12), 5-8 yrs (N = 9), and 8-15 yrs (N = 7). All subjects had worm a cochlear implant for at least 24 mos, and an average of 36 mos. All subjects used simultaneous communication at the time of implantation. Subjects performed both imitative and structured spontaneous sampling speech tasks. The results permit the following conclusions: (a) children who have used a cochlear implant for at least 2 yrs acquire some intelligible speech; (b) children who receive a cochlear implant before the age of 5 yrs appear to show greater benefit in their speech production skills than children who are older, at least after a minimum of 2 yrs of use; (c) children who recognize more speech while wearing their cochlear implants are likely to speak more intelligibly; and, (d) signing does not disappear from a child's communication mode following implantation.

How do nurses deal with their own grief when a patient dies on an intensive care unit, and what help can be given to enable them to overcome their grief effectively?

There is an expectation that nurses are good at caring for relatives on the death of a patient. Who, though, cares for the nurses? Using both a quantitative and a qualitative approach, this study looks at how nurses overcome their own grief when a patient dies on an intensive care unit. Information was first collected using a questionnaire. Personal grief, however, is a very emotive area, so a proportion of the nurses from the initial study were then asked to take part in a semi-structured interview, to explore their feelings in more depth. The quantitative data were analysed using the computer software Statistical Package for the Social Sciences and the results were related to the interview responses. This showed how nurses deal with their grief, and that many, but not all, felt that the informal support network already present was sufficient. Some nurses, however, felt that a support group would also be helpful and some felt the availability of a counsellor would be useful. All nurses felt that more training about how to deal with their own grief was needed.

Evaluation of the double diffusion, enzyme immunoassay and immunoblotting techniques, for the diagnosis of human hydatid disease in tropical areas

Hydatid disease in tropical areas poses a serious diagnostic problem due to the high frequence of cross-reactivity with other endemic helminthic infections. The enzyme-linked-immunosorbent assay (ELISA) and the double diffusion arc 5 showed respectively a sensitivity of 73% and 57% and a specificity of 84-95% and 100%. However, the specificity of ELISA was greatly increased by using ovine serum and phosphorylcholine in the diluent buffer. The hydatic antigen obtained from ovine cyst fluid showed three main protein bands of 64, 58 and 30 KDa using SDS PAGE and immunoblotting. Sera from patients with onchocerciasis, cysticercosis, toxocariasis and Strongyloides infection cross-reacted with the 64 and 58 KDa bands by immunoblotting. However, none of the analyzed sera recognized the 30 KDa band, that seems to be specific in this assay. The immunoblotting showed a sensitivity of 80% and a specificity of 100% when used to recognize the 30 KDa band.

Pre- and post-treatment immunodiagnostic evaluation in human schistosomiasis mansoni

Schistosomiasis control seems to be different in countries were low parasitic burden and asymptomatic clinical patients are the features of majority of cases. Immunological methods must substitute the traditional coprologic techniques used for some decades in the Control Program. Circumoval Precipitin Test (COPT), intradermal test and ELISA with soluble egg antigen (SEA) are evaluated for using as tools for seroepidemiologic studies. COPT and ELISA were performed after treatment to known their utility when impact of chemotherapy must be assessed. One hundred sixty five persons were followed up 3, 6, 9 and 12 months after treatment. The mean sensitivity of COPT studied by age groups was 95.6% which is very important considering that 88.4% of the studied population excreted less than 100 eggs/gr of feces, while sensitivity of intradermal test was 58.2%. Children showed the highest reactivity to COPT. When treatment is effective, COPT reactivity progressively diminish until become negative one year later. In the non cure group, the COPT reactivity diminished but never below 20%. ELISA-SEA did not modify one year after treatment. Effort should be made to isolate fractions of eggs of Schistosoma mansoni whose antibodies disappear after treatment.

Mice immunized with a synthetic peptide construct corresponding to an epitope present on a Plasmodium falciparum antigen are protected against Plasmodium chabaudi challenge

Inhibitory monoclonal antibody (MoAb) 8E7/55 recognizes a parasitophorous vacuole membrane (PVM) antigen in Plasmodium falciparum. Previous studies have identified the epitope, DNNLVSGP, recognized by the MoAb. A synthetic peptide containing this sequence was synthesized and coupled to diphtheria toxoid (DT) and was found capable of generating antibodies when used as an immunogen in mice which recognize the native antigen exp-1. In this study we demonstrate the ability of the MoAb and antisera generated against the peptide construct to recognize a 54 kD PVM antigen in Plasmodium chabaudi. The P. chabaudi antigen is synthesized in trophozoites and released to the surrounding culture media outside the parasitized erythrocyte. Mice immunized with the peptide conjugate are protected when challenged with a lethal strain of P. chabaudi. Protection in the mice correlated with the antibody titre prior to challenge. If the PVM antigen from P. chabaudi is a homologue of exp-1 from P. falciparum, then these experiments may provide a guide to the antibody titres required in human trials before antibody mediated protection could be expected. The discovery that a PVM localized antigen is secreted into the surrounding in vitro culture media provides us with a valuable model system for further investigation of protein trafficking pathways in malaria-infected erythrocytes.