The influence of long-term tracheostomy on speech and language development in children

BACKGROUND

Individuals diagnosed as having primary neurological disorders have a high incidence of abnormal speech and language development. However, results in cohorts where this group are excluded are controversial. With no coexisting neurological impairment, some suggested that tracheostomy has little influence on speech development, whilst others showed a clear pattern of language disability. The aim of this study is to evaluate the influence of tracheostomy on speech and language development.

METHOD

Retrospective study using standardised outcome measures.

RESULTS

A series of 39 paediatric tracheostomies was studied. In the group where children had neurological disorders, 94% showed no language or delayed language development. In contrast, of the group of children without a neurological impairment, 60.9% had normal speech and language development. The median age at the decannulation in those children with delayed speech was 23 months, whilst in those children with normal speech it was 14.5 months.

CONCLUSION

Tracheostomy affects speech and language development in those with and without neurological disorders. Crucial factors affecting speech and language development within the neurologically normal group are age at the tracheostomy, and the duration of the tracheostomy until decannulation. Achieving earliest decannulation improves the chance of a normal speech and language development.

Carbon monoxide concentrations in paediatric sepsis syndrome

Plasma carbon monoxide (CO) concentrations were measured in 12 patients with sepsis syndrome. CO concentrations were found to be significantly increased in patients compared with those in 30 normal controls. Patients with septic shock had significantly higher plasma CO concentrations than those without shock. Results suggest that CO might play an important role in paediatric sepsis syndrome.

Anti-endothelial cell antibodies in Behçet's disease

OBJECTIVE

Circulating antibodies that bind to human endothelial cells cultured in vitro have been detected in a variety of diseases, including Behçet's disease. In this disorder the reported prevalence of AECA has varied widely. One likely source of variability is the ELISA assay itself, in which differing conditions and reagents have been used in different reports.

METHODS

We have re-examined the frequency of AECA in 132 Turkish Behçet's patients and 50 healthy Turkish controls, comparing several different methods of preparing the target endothelial cells. Human umbilical vein endothelial cells (HUVEC) were used either: 1) fresh and non-treated, 2) fixed, or 3) TNF alpha-stimulated. All stages of the procedures were performed at room temperature.

RESULTS

In Behçet's patients, using fresh, non-treated HUVEC, 17 of 130 (13.1%) and 9 of 132 (6.8%) sera were positive for IgG- and IgM-AECA, respectively. However, among 50 normal controls, 2 (4.0%) had IgG-positive and 4 (8.0%) had IgM-positive ELISAs under the same conditions. The difference in the frequency of positives between patients and controls was not statistically significant. Fixed HUVEC and TNF alpha-treated HUVEC gave similar results as well. When group means were examined, only the mean for IgG-AECA determined with TNF alpha-stimulated HUVEC reached statistical significance.

CONCLUSION

The discrepancy between our data and earlier reports in the literature probably reflects the methodological differences alluded to, and highlights the difficulties in interpreting ELISA assays for AECA.

Frequencies of the major alleles of the Diego, Dombrock,Yt, and Ok blood group systems in the Chinese Han, Hui, and Tibetan nationalities

The frequencies of the major alleles of the Diego,Dombrock,Yt,and Ok blood group systems in the Chinese Han, Hui, and Tibetan nationalities were determined using a DNA-based PCR-sequence-specific primers (SSP) genotyping technique. The frequencies of Dia, Dib, Doa, and Dob genes were 0.0295, 0.9705, 0.1159, and 0.8841 in 220 Chinese North Han, respectively. The Yta gene frequencies were 0.9928, 0.9917, and 0.9983 in 277 Han, 300 Hui, and 303 Tibetan blood donors, respectively. No Ok(a-) individuals were found in 304 Han, 300 Hui, and 303 Tibetan individuals.

[Effects of Ganoderma lucidum (Leyss ex Fr) Karst compound on the proliferation and differentiation of K562 leukemic cells]

A series of experiments including cell culture and benzidine staining test were undertaken to investigate the effects of Ganoderma lucidum(Leyss ex Fr) Karst Compound(GLC) on the proliferation and differentiation of K562 leukemic cells. The results showed that different concentrations of GLC(from 4 mg.ml-1 to 12 mg.ml-1) could promote human bone marrow granulocyte-macrophage colony forming unit (CFU-GM) proliferation, but suppressed the growth of K562 leukemic cell colonies, and IC50 was 9.2 mg.ml-1. The data from liquid culture demonstrated that GLC could suppress K562 cells proliferation in a dose-dependent(from 4 mg.ml-1 to 20 mg.ml-1) and time-dependent(from 1-5 days) manner. K562 cells could be induced to differentiate into more mature erythrocytic cells by 4 mg.ml-1 and 8 mg.ml-1 GLC. It is concluded that GLC may be a good medicine for leukemia therapy.

Survival in transgenic ALS mice does not vary with CNS glutathione peroxidase activity

OBJECTIVE

Transgenic mice that overexpress a human gene encoding mutant cytosolic superoxide dismutase (SOD1) develop a progressive motor neuron loss that resembles human ALS. Why mutant SOD1 initiates motor neuron death is unknown. One hypothesis proposes that the mutant molecule has enhanced peroxidase activity, reducing hydrogen peroxide (H2O2) to form toxic hydroxyl adducts on critical targets. To test this hypothesis, the authors generated transgenic ALS mice with altered levels of glutathione peroxidase (GSHPx), the major soluble enzyme that detoxifies H2O2.

METHODS

SOD1(G93A) ALS mice were bred with mice bearing a murine GSHPx transgene that have a four-fold elevation in brain GSHPx levels and with mice having targeted inactivation of the GSHPx gene and reduced brain GSHPx activity.

RESULTS

Survival was not prolonged in ALS mice with elevated brain GSHPx activity (p = 0.09). ALS mice with decreased GSHPx brain activity (20% of normal) showed no acceleration of the disease course (p = 0.89). The age at disease onset in the ALS mice was unaffected by brain GSHPx activity.

CONCLUSION

The level of GSHPx activity in the CNS of transgenic ALS mice does not play a critical role in the development of motor neuron disease.

[The clinical application of perfluorotributylamine liquid in the complicated retinal detachment]

OBJECTIVE

To evaluate the clinical application value of perfluorotributylamine liquid (PFTL) made in China in the complicated retinal detachment.

METHODS

PFTL was injected into eyeball after vitreoretinal surgery, it could open funnel of retinal detachment, push subretinal fluid out from peripheral hole and flat and immobilize the posterior retinal during vitreoretinal surgery. In eyes with giant tears, PFTL could unfold and fix retinal flap.

RESULTS

The retinas in all cases with giant tears were reattached, and sixty per cent in the eyes with PVR-D2-D3 reattached. In 8 eyes the visual acuity was improved.

CONCLUSION

PFTL is valuable in treatment of complicated retinal detachment. It facilitates vitreoretinal surgery, obviates the potential complications.

[Immunogenicity of retina in mice]

OBJECTIVE

To evaluate the immunogenicity of retina.

METHODS

DBA/2 mice (MHCH-2d) were used as donors, C57BL/6 mice (MHC H-2d) or BALB/C mice (MHC H-2d) as recipients. Half retina of DBA/2 mouse was transplanted subcutaneously to a C57BL/6 or BALB/C mouse. The delayed-type hypersensitivity (DTH) and specific killing rate of cytotoxic T lymphocyte(CTL) were detected two weeks later.

RESULTS

The results of DTH and specific killing rate of CTL in the retina of DBA/2 mice were significantly lower than the positive group(P < 0.01), but significantly higher than the negative group(P < 0.01).

CONCLUSION

MHC Class I and Class II antigen and minor histocompatibility complex antigen(Minor HC) are expressed in the retina of the DBA/2 mouse, which stimulates immune system of recipient to produce weak cellular immune response. It is suggested that the retina has weak immunogenicity.

[Effects of cytokines and umbilical cord blood preserved at 4 degrees C on the growth of CFU-GM and HPP-CFC]

We studied the effects of different cytokine combinations and umbilical cord blood preserved at 4 degrees C for 4 days on the growth of CFU-GM and HPP-CFC. The results showed that the growth of umbilical cord blood CFU-GM was markedly different when various combinations of cytokines were used. After 2 weeks culturing with IL-3 alone or plus GM-CSF, the number of umbilical cord blood CFU-GM was increased when compared with GM-CSF group; upon stimulation with GM-CSF plus IL-3 plus IL-6 plus Epo, a significant increase of umbilical cord blood CFU-GM was seen. After umbilical cord blood being preserved 4 days at 4 degrees C, the number of umbilical cord blood CFU-GM and HPP-CFC was decreased.

Zn(2+) induces permeability transition pore opening and release of pro-apoptotic peptides from neuronal mitochondria

Rapid entry of Ca(2+) or Zn(2+) kills neurons. Mitochondria are major sites of Ca(2+)-dependent toxicity. This study examines Zn(2+)-initiated mitochondrial cell death signaling. 10 nm Zn(2+) induced acute swelling of isolated mitochondria, which was much greater than that induced by higher Ca(2+) levels. Zn(2+) entry into mitochondria was dependent upon the Ca(2+) uniporter, and the consequent swelling resulted from opening of the mitochondrial permeability transition pore. Confocal imaging of intact neurons revealed entry of Zn(2+) (with Ca(2+)) to cause pronounced mitochondrial swelling, which was far greater than that induced by Ca(2+) entry alone. Further experiments compared the abilities of Zn(2+) and Ca(2+) to induce mitochondrial release of cytochrome c (Cyt-c) or apoptosis-inducing factor. In isolated mitochondria, 10 nm Zn(2+) exposures induced Cyt-c release. Induction of Zn(2+) entry into cortical neurons resulted in distinct increases in cytosolic Cyt-c immunolabeling and in cytosolic and nuclear apoptosis-inducing factor labeling within 60 min. In comparison, higher absolute [Ca(2+)](i) rises were less effective in inducing release of these factors. Addition of the mitochondrial permeability transition pore inhibitors cyclosporin A and bongkrekic acid decreased Zn(2+)-dependent release of the factors and attenuated neuronal cell death as assessed by trypan blue staining 5-6 h after the exposures.

[Analgesic effect induced by stimulation of rats brain with strong pulsed magnetic field: a preliminary study]

The Objective of this study was to determine whether stimulation on the brain of SD rats with strong pulsed magnetic field could produce analgesic effect. A stimulator of CADWELL (MES-10) was adopted in the study. The pain index used was the Tail Flick Latency (TFL) of rats. The stimulation parameters were: (1) the intensity percent (20%) and stimulation duration (7 min); (2) the intensity percent (30%) and stimulation duration (3 min). The results showed that the mean Acquired TFL change was 23% (P < 0.01) for the 20% intensity group, and 26% (P < 0.01) for the 30% intensity group.

CONCLUSION

These data indicate that the new method for analgesia is effective, and compared with other approaches to stimulation analgesia, this one is non-invasive, easy to operate, and less causative of discomfort.

[Nonlinear behavior of nerve fibers with constant current stimulation]

There are abundant nonlinear phenomenons in life systems. Using the Hodgkin-Huxley model, we studied the excitability of single nerve fiber under constant current stimulation by means of computer simulation. It was found that stimulated with different current intensities, the membrane potentials of the nerve fiber are at equilibrium points or periodic oscillations. And the frequencies of the periodic oscillations are obtained.

Protection of xenogeneic cells from human complement-mediated lysis by the expression of human DAF, CD59 and MCP

CD59 and membrane cofactor protein (MCP, CD46) are widely expressed cell surface glycoproteins that protect host cells from the effect of homologous complement attack. cDNAs encoding human CD59 and MCP cloned from Chinese human embryo were separately transfected into NIH/3T3 cells resulting in the expression of human CD59 and MCP protein on the cell surface. The functional properties of expressed proteins were studied. When the transfected cells were exposed to human serum as a source of complement and naturally occurring anti-mouse antibody, they were resistant to human complement-mediated cell killing. However, the cells remained sensitive to rabbit and guinea pig complement. Human CD59 and MCP can only protect NIH/3T3 cells from human complement-mediated lysis. These results demonstrated that complement inhibitory activity of these proteins is species-selective. The cDNAs of CD59 and MCP were also separately transfected into the endothelial cells (ECs) of the pigs transgenic for the human DAF gene to investigate a putative synergistic action. The ECs expressing both DAF and MCP proteins or both DAF and CD59 proteins exhibited more protection against cytolysis by human serum compared to the cells with only DAF expressed alone.

Selective stimulation of smaller nerve fibers using biphasic rectangular pulses

Based on the F-H model, a simulation system to study the excitation properties of myelinated nerve fibers was developed. In order to minimize electrochemical damage of nerve tissue, three selective stimulation methods employing biphasic rectangular pulses were studied, which use single, double and triple electrodes, respectively. The simulation results prove that all of the three methods are effective in selective stimulation of smaller nerve fibers in a compound nerve trunk under certain conditions. The feasibility of these methods is also verified by animal experiments on the sciatic nerve trunks of toads. The amplitude and delay of compound action potential and the results of collision experiments proved that the methods are valid. These methods will be very useful in functional neuromuscular stimulation.

[A study on quantitative assessment of osteoporosis based on texture analysis]

A quantitative assessment on osteoporosis by using texture analysis has been developed on the basis of coherence mapping, two-dimensional power spectral estimation with modulated transfer function correction and fractal features analysis on trabecular pattern of bone X-ray images. Three objective features of trabecular pattern are selected to form a feature set that can be used in automatic classification for two grades of bone: normal bone and the bone with a medium degree of osteoporosis. This set of features is extracted from each of 16 sample bone X-ray images. With the use of Euclidean norm in the feature space, a center of cluster of each grade of bone is defined as the prototype. For each bone X-ray image, the distance from its features to the two prototypes in feature space is computed to provide an objective judgement on the degree of osteoporosis. The machine classification of 10 bone X-ray images based on the developed prototype is given, and the result indicates that the proposed method is potentially applicable to the objective diagnosis of osteoporosis.

[Improvement of coils used in functional magnetic stimulation]

OBJECTIVE

Functional magnetic stimulation (FMS) is a new technique for stimulating the excitable tissue. But the difficulty to locate the activation point and the poor capability of focusing limit the further progress of FMS. A new stimulation method using 8-shaped coil and a combinatorial coil were presented to improve coils performance.

METHOD

The distribution of the induced electrical field was calculated based on Faraday law.

RESULT

When the nerve was perpendicular to the handle of 8-shaped coil and tangential to the coil edge, the position with the maximum of first spatial gradient of the field did not change with the varying of the radius of coil and the excitation depth; the values of the first spatial gradient of field above the stimulation target decreased obviously using the combinatorial coils.

CONCLUSION

Comparing with the current stimulation method of 8-shaped coil, the new method gave a fixed activation point. The capability of focusing was improved using the presented combinatorial coil.

Fatty acid synthesis in African trypanosomes: a solution to the myristate mystery

The glycosyl phosphatidylinositol anchor of the trypanosome variant surface glycoprotein contains myristate as its sole fatty acid component. Surprisingly, there does not appear to be enough myristate in either the parasite or its host's bloodstream to sustain myristoylation of the enormous quantity of variant surface glycoprotein produced. Here, we discuss how the trypanosome solves its myristate dilemma. The parasite not only efficiently salvages and processes myristate from the bloodstream, but it also makes myristate de novo using a recently discovered specialized fatty acid synthesis system.

[The technical method for noninvasive magnetic stimulation of nerve center and its clinical application]

The increasing use of non-invasive magnetic stimulation technique for nerve center function examination and functional neuromuscular rehabilitation is a new cynosure in biomedical engineering and neuro-electrophysiologic researches. This paper analyzes theoretically the magnetic stimulation of first demonstration extending the technique model to human body, and the magnetic principle of physics. The characteristics of magnetic stimulation can be highlighted by comparing it to conventional electrical stimulation. Also presented are the peripheral multichannel magnetic stimulation to mimic electrical stimulation and the clinical functions toward neuromuscular rehabilitation.

Genomic organization of BmTXKbeta and BmTXKS2, two scorpion venom peptides from Buthus martensii Karsch

To elucidate genomic organization of BmTXKbeta and BmTXKS2, two scorpion venom peptides from Chinese scorpion Buthus martensii Karsch(BmK) were first isolated and their genomic regions characterized using the PCR method. Analysis of nucleotide sequence shows that there exists different intron location in the venom genes. The region encoding mature peptide of BmTXKbeta is disrupted by an intron with 886 bp, whereas the intron of BmTXKS2 is located within its propeptide coding region, which is different from other scorpion toxin genes with their introns within the signal peptide coding region.

A neural code for low-frequency sound localization in mammals

We report a systematic relationship between sound-frequency tuning and sensitivity to interaural time delays for neurons in the midbrain nucleus of the inferior colliculus; neurons with relatively low best frequencies (BFs) showed response peaks at long delays, whereas neurons with relatively high BFs showed response peaks at short delays. The consequence of this relationship is that the steepest region of the function relating discharge rate to interaural time delay (ITD) fell close to midline for all neurons irrespective of BF. These data provide support for a processing of the output of coincidence detectors subserving low-frequency sound localization in which the location of a sound source is determined by the activity in two broad, hemispheric spatial channels, rather than numerous channels tuned to discrete spatial positions.

[Experimental study on immune privilege in subretinal space]

OBJECTIVE

To evaluate the immune characteristics of subretinal space.

METHODS

Retina of DBA/2 mouse with or without Complete Freund's Adjunvate (CFA), or human peripheral blood mononuclear cell (PBMC), or syngenic retina, and DMEM as negative control were transplanted into subretinal spaces of BALB/C mouse. Delayed-type hypersensitivity (DTH) and specific killing of cytotoxic T lymphocyte (CTL) were detected two weeks later and histopathological examination was carried out as well.

RESULTS

There were no significant differences in DTH between four experimental groups and control group, but the specific killing of CTL was significantly higher than that of the control group. Retinal transplant was survival. Immune rejection occurred in human PBMC group.

CONCLUSION

Limited immune privilege occurs in a certain degree after subretinal space transplantation.