Polymorphisms and the differential antiviral activity of the chicken Mx gene

The nucleotide sequence of chicken Mx cDNA was reported earlier using the White Leghorn breed in Germany, but it showed no enhanced resistance to viruses. In this study, the nucleotide sequences of chicken Mx cDNA were determined in many breeds. A total of 25 nucleotide substitutions, of which 14 were deduced to cause amino acid exchanges, were detected, suggesting that the chicken Mx gene is very polymorphic. Transfected cell clones expressing chicken Mx mRNA were established after the Mx cDNA was constructed with an expression vector and introduced into mouse 3T3 cells, and the Mx genes from some breeds were demonstrated to confer positive antiviral responses to influenza virus and vesicular stomatitis virus. On the basis of the comparison among the antiviral activities associated with many Mx variations, a specific amino acid substitution at position 631 (Ser to Asn) was considered to determine the antivirally positive or negative Mx gene. Thus, a single amino acid substitution influences the antiviral activity of Mx in domesticated chickens.     

Generation of B lymphocytes from a single hemopoietic progenitor cell in vitro

The first stages of the pathway by which lymphocytes differentiate from hemopoietic stem cells were studied at a clonal level. When 211 interleukin 3 (IL-3)-induced blast colonies shown to be capable of differentiating into a variety of hemopoietic cells were individually transferred into wells containing a monolayer of stromal cells, growth in granulocyte, macrophage, megakaryocyte, or mast cell lineages was observed in 192 wells. In seven of these 192 wells, lymphoid cell growth also was seen. The lymphoid cells were proved to be B lymphocytes by phenotype and immunoglobulin gene rearrangement analyses and by demonstration of surface expression of IgM. The clonal origin of myeloid and B lymphocyte lineage cells was further confirmed by the generation of both myeloid and B lymphoid cells in the same well following FACS clone-sorting of IL-3 induced blast cells. These results provide in vitro evidence that cells of B lymphoid and myeloid lineage can originate clonally from single primitive hemopoietic stem cells.     

Environmental monitoring and assessment of short-term exposures to hazardous chemicals of a sterilization process in hospital working environments

In order to assess short-term exposures to ethylene oxide, formaldehyde and glutaraldehyde in a sterilization process, the authors conducted continuous environmental monitoring of these chemicals in the breathing zone of workers in 2 hospitals. The arithmetic mean of ethylene oxide was 1.2 ppm near unventilated cabinets housing sterilizing materials, and environmental concentrations of ethylene oxide could not be reduced under threshold limit values time weighted average by only managing general ventilation. Environmental concentration of formaldehyde was lower in a properly ventilated pathology division in which no large specimens were stored (0.3 ppm) than in the pathology division where large specimens were stored (2.3 ppm). Although environmental concentrations of glutaraldehyde in an endoscopy unit with proper general ventilation were not detectable, environmental concentration levels in an endoscopy unit without general ventilation system were 0.2 and 0.5 ppm. According to the results of environmental monitoring in the breathing zone of workers, extremely high concentrations were observed in some work practices (ethylene oxide, 300 ppm; formaldehyde, 8.6 ppm; glutaraldehyde, 2.6 ppm). In order to avoid occupational exposures to these chemicals and prevent potential chronic and acute health hazards, good communications with these chemicals, good work practices, appropriate personal protective equipment, and engineering controls should be required.     

Reliability of the acetabular teardrop as a landmark

Summary This study investigated the effect of tilt and observer reliability on radiographic measurements of the position of a prosthetic acetabular cup in seven dry bone pelves using the teardrop as a landmark. Coronal or sagittal tilt of more than five degrees was easily recognisable and there was effectively no observer variation in the measurements up to this limit. In addition, 90 out of 100 randomly selected antero-posterior pelvic radiographs from an outpatient department were not significantly rotated and 93 demonstrated a clearly defined teardrop. Measurements about the teardrop on routine radiographs are therefore sufficiently accurate to allow assessment of prosthetic position.

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La valeur du sourcil cotyloidien comme repère d'analyse radiologique

Résumé Cette étude, conduite sur 7 bassins secs, apprécie l'effet de l'inclinaison du bassin sur la qualité de l'analyse radiographique de la position d'une cupule prothétique de hanche en utilisant le sourcil cotyloïdien comme repère. Une inclinaison du bassin dans les plans coronal et sagittal est aisément détectable et il n'existe pas de variation d'analyse entre les différents observateurs en dessous de 5° d'inclinaison. De plus, sur 100 radiographies antéro-postérieures de bassin choisies au hasard dans les dossiers de consultation, 90 avaient été réalisées sans incidence particulièrement adaptée et l'on pouvait repérer facilement le sourcil sur 93% d'entre elles. Les mesures faites sur des radios de routine sont donc suffisamment précises pour permettre l'évaluation de la position d'une prothèse à partir du sourcil cotyloïdien.

     

Leader (L) and L* proteins of Theiler's murine encephalomyelitis virus (TMEV) and their regulation of the virus' biological activities

Theiler's murine encephalomyelitis virus (TMEV) is divided into two subgroups on the basis of their different biological activities. GDVII subgroup strains produce fatal poliomyelitis in mice without virus persistence or demyelination. In contrast, TO subgroup strains induce demyelinating disease with virus persistence in the spinal cords of weanling mice. Two proteins, whose open reading frames are located in the N-terminus of the polyprotein, recently have been reported to be important for TMEV biological activities. One is leader (L) protein and is processed from the most N-terminus of the polyprotein; its function is still unknown. Although the homology of capsid proteins between DA (a representative strain of TO subgroup) and GDVII strains is over 94% at the amino acid level, that of L shows only 85%. Therefore, L is thought to be a key protein for the subgroup-specific biological activities of TMEV. Various studies have demonstrated that L plays important roles in the escape of virus from host immune defenses in the early stage of infection. The second protein is a 17–18 kDa protein, L*, which is synthesized out-of-frame with the polyprotein. Only TO subgroup strains produce L* since GDVII subgroup strains have an ACG rather than AUG at the initiation site and therefore do not synthesize L*. 'Loss and gain of function' experiments demonstrate that L* is essential for virus growth in macrophages, a target cell for TMEV persistence. L* also has been demonstrated to be necessary for TMEV persistence and demyelination. Further analysis of L and L* will help elucidate the pathomechanism(s) of TMEV-induced demyelinating disease.     

The therapeutic effects of aspoxicillin on various infectious diseases in children

Clinical application to ascertain the effects of aspoxicillin (ASPC), a new semisynthetic penicillin antibiotic, upon several infectious diseases of children was performed in 7 cases with pneumonia, 5 cases with acute bronchitis, each case with tonsillitis, enterocolitis, urinary tract infection and suspected sepsis. ASPC was injected by drip infusion and the dosage was 63-117 mg/kg/day in 3 and 4 times a day. Clinical efficacy obtained as "excellent" was in 7 cases, "good" in 8 cases "poor" in 1 case, and efficacy rate was 93.8%. From the bacteriological point of view, eliminated in each of H. influenzae, H. parainfluenzae, group A beta-Streptococcus and unchanged in a case of E. coli. There were transient thrombocytopenia in 2 cases and eosinophilia in 3 cases.     

Clinical experience with ceftizoxime suppositories in pediatrics

Ceftizoxime suppositories (CZX-S), containing 250 mg or 125 mg of CZX, were given to 6 children, 4 with acute bronchopneumonia and 2 with acute pharyngobronchitis, who were not suited to treatment with injectable or oral form of the drug. The clinical response was "good" in all the children and the causative organisms were eradicated in 2 children (H. influenzae or S. aureus). Adverse reactions consisted of 1 case each of diarrhea and transiently increased GPT. In conclusion, CZX-S proved to be highly effective in the treatment of bacterial infections in children.     

Observation of CSF pulsatile flow in MRI--the signal void phenomenon

In a comparative study of MR images of 289 neurosurgical patients, loss of the signal intensity (signal void phenomenon) of CSF in the aqueduct was observed in 77 patients. This signal void phenomenon was seen most frequently in infants with chronic subdural hematoma (12 of 18) and patients of all age groups suffering from communicating hydrocephalus (10 of 14). It is known that CSF in the cranial cavity flows toward the spinal CSF space in to and fro manner responding to brain parenchyma pulsations. The velocity of this flow is to be faster in the narrower parts through the ventricular systems such as the aqueduct, Monro's foramen and the 4th ventricles. We think that in T2 weighted images signal void phenomenon reflects "high velocity signal loss" due to CSF flow. When the subarachnoid adhesions secondary to subarachnoid hemorrhage stagnate CSF flow in the subarachnoid space, the intraventricular CSF flow forms the main buffer for changes of the brain volume. This causes an increase in the amplitude of the pulsatile flow in the ventricular systems. Therefore the signal void phenomenon in the aqueductal CSF becomes more pronounced. It may be possible to differentiate normal circulation of CSF from abnormal with the bigger amplitude of CSF pulsatile flow, to understand the mechanisms of the normal pressure hydrocephalus or to diagnose a shunt malfunction. Therefore more insight in the CSF flow as imaged by MRI is needed, quantification of CSF flow will be the subjects of our further research.