Biology of Mouse Thymic Virus, a Herpesvirus of Mice, and the Antigenic Relationship to Mouse Cytomegalovirus

Mouse thymic virus (TA) is a herpesvirus which produces extensive necrosis of the thymus of newborn mice 7 to 14 days after infection. Infectious virus can be recovered from the thymus for only 10 days after infection, with highest titers occurring between days 5 and 7. In mice 5 days old or less, TA infects thymus cells and produces massive necrosis. TA also infects the salivary glands and persists as a chronic infection. Newborn mice infected with TA have no detectable humoral immune response. Infected adult mice respond, and humoral antibody is detected 7 days after infection. Titers are maintained for months thereafter. Regardless of the age of the mice inoculated with TA, persistent infection was established in the salivary glands, but no evidence for thymus involvement was observed when adults were infected. TA does not cross-react serologically by immunofluorescent, complement fixation, or virus neutralization tests with mouse cytomegalovirus; however, interestingly, the epidemiology of the two herpesviruses are similar. Both mouse cytomegalovirus and TA were isolated from the same animals in populations of laboratory and wild mice. Evidence of infection with mouse cytomegalovirus and TA were most apparent by virus isolations, since humoral antibody responses are rarely observed. All strains of mice tested were susceptible to TA infection. However, in some strains maximum necrosis occurred at 7 days, compared with 10 to 14 days for other strains. The difference in age susceptibility and the target tissue of thymus in newborn mice suggests that TA is a model herpesvirus for studying the effects of viral infections on humoral and cell-mediated immunological functions.     

Relationship between conjugate lateral eye movements and alexithymia.

The relationship between conjugate lateral eye movements (CLEMs) and alexithymia was investigated in a group of 60 (23 male and 37 female) right-handed university students. Subjects completed the Toronto Alexithymia Scale (TAS), the Schalling-Sifneos Personality Scale, and the Basic Personality Inventory, which measures 12 basic dimensions of personality and psychopathology, CLEMs were recorded while subjects were asked 20 general knowledge questions that have no tendency to elicit eye movements predominantly in one direction. A series of gender by CLEM preference (left vs. right mover) ANOVAs were conducted with the various measures. There was a significant relationship between right CLEM preference and higher scores on the TAS, but no relationships between CLEMs and any of the other measures. These results suggest that alexithymia is associated with left cerebral lateralization, and support the hypothesis that alexithymic characteristics reflect a variation in brain organization.     

Formaldehyde in cryoprotectant propanediol and effect on mouse zygotes

Cryopreservation of human zygotes and embryos has been routinely performed by in-vitro fertilization clinics for many years. Karran and Legge (1996) first reported that formaldehyde (FA) present in the cryoprotective solutions can have a deleterious effect on mouse oocytes. FA is a cytotoxic, carcinogenic and mutagenic chemical. The effect of FA on mouse zygotes was investigated. In addition, the concentrations of FA in propanediol (PROH) obtained from various sources were determined. Pooled 1-cell embryos were dispensed into droplets of modified Ham's F10 or human tubal fluid containing various concentrations of FA. Since bovine serum albumin (BSA) may minimize toxicity additional trials were done as above in the absence of BSA. FA concentration in the standard 1.5 M PROH, from different sources in water, was measured in the same assay using a standard curve of 0-100 microM FA. FA in a complex medium had a significant deleterious effect on embryo development and hatching but only at 1 mM concentration (P < 0.000001; see Tables I-III). There was no significant effect of FA at 100 microM. However, in a simple medium even 50 microM FA decreased embryo hatching. FA was present in 1.5 M PROH from different sources (range 1.0-35.3 microM concentration). It appears that FA concentrations do not increase with storage because FA concentrations were low even after opening and storage for 3 years on the shelf. This suggests that FA is a contaminant during the manufacturing process and may vary from manufacturer to manufacturer and batch to batch. Until further studies are done to confirm the lack of toxicity to embryos during cryopreservation (with or without FA scavengers) it may be prudent to screen all batches of cryoprotectants for FA as part of quality control.      

Absence of simian virus 40 (SV40) DNA in lymphoma samples from Tasmania, Australia

AIMS: It has been postulated that the recent world-wide increase in the incidence of non-Hodgkin's lymphoma (NHL) may have been caused by human infection with simian virus 40 (SV40) (a lymphotropic monkey virus that was introduced to man from contaminated poliovirus vaccines between 1955 and 1963); therefore, we set out to determine the incidence of SV40 DNA positivity in lymphoma samples from patients in Tasmania, Australia. METHODS: One hundred lymph node samples, 50 from patients with lymphomas and 50 from controls, were tested using PCR amplification of three SV40-specific primer pairs followed by dot-blot hybridisation. RESULTS: All of the samples tested contained amplifiable DNA, but none contained amplifiable SV40 sequences with any of the primer sets used. CONCLUSIONS: Our results demonstrate absence of SV40 in the lymphoid tissues of our study population in Tasmania, Australia. SV40 does not explain the increasing incidence of NHL in our population.     

Confidentiality and serious harm in genetics - preserving the confidentiality of one patient and preventing harm to relatives

Genetics can pose special challenges to the principle of confidentiality within the health professional-patient relationship, since genetic information is by its nature both individual and familial. Most professional guidelines allow confidentiality to be broken in rare circumstances, where it will prevent a 'serious', 'imminent' and 'likely' harm. We argue that the types of harms that may result from genetic medicine are particularly diverse. Using clinical examples, we explore ethical issues that arise when balancing individual and family member interests. As genetic testing becomes more, widespread situations will arise where clinicians are faced with a choice between preserving the confidentiality of one patient and preventing harm to another. Professionals need to incorporate the notion of familial implications in their counseling of individuals. Since such dilemmas have been relatively rare in the pre-genetic age, we call for a wider debate on the balance between confidentiality and harm to others.     

Inclusion of CpG adjuvant with plasmid DNA coding for NcGRA7 improves protection against congenital neosporosis

The present study showed that incorporation of CpG adjuvant into plasmid DNA coding for NcGRA7 antigen resulted in a twofold increase in the level of protection against congenital transfer of Neospora caninum. The level of protection was considerably higher than that observed in pups born from dams immunized with nonrecombinant plasmid.     

Silica-filled elastomer/methacrylate systems as soft liners

Denture soft lining materials are compliant cushions used at the oral tissue-denture interface. They are generally required to have sufficient compliance to redistribute mastication load, as well as an adequate modulus for long-term dimensional stability and control over the water uptake. This study investigated the effect of using silane treated fumed silica as a filler on the properties of experimental soft lining materials based on blends of isoprene-styrene (SIS) block co-polymer and mixtures of methyl methacrylate (MMA) and 1,6-hexandiol dimethacrylate (HDMA). The overall elastomer/monomer ratios were maintained, whereas the monomers ranged from 10 to 60% HDMA. The silica filler level was maintained at 10 wt% with respect to SIS. The properties investigated were the dynamic mechanical parameters of storage modulus (E') and tan delta as a function of temperature and the quasi-static mechanical parameters of ultimate tensile strength (UTS) and elongation to break (Eb) as well as absorption properties that were carried out in water and saline. In both unfilled and filled systems there was an increase in E' and a decrease in tan delta with an increase in HDMA. Silica addition tended to increase E' and substantially reduce tan delta in materials with less than 20% HDMA. UTS decreased with filler and HDMA content, however, Eb was greater for filled systems. Generally, in the long term, the water uptake decreased with increasing HDMA content and E'. The silanated silica further reduced the water uptake, indicating a cross-linking effect, thus increasing the restraining force on droplet growth. The uptake in saline was significantly reduced indicating an osmotically controlled uptake process.     

Bilateral microphthalmia with cyst,facial clefts,and limb anomalies: a new syndrome with features of Waardenburg syndrome,cerebro-oculo-nasal syndrome,and craniotelencephalic dysplasia

We report a patient with bilateral microphthalmia with cyst, limb anomalies, and multiple facial malformations. This patient has clinical features similar to Waardenburg ophthalmo-acromelic syndrome, cerebro-oculo-nasal syndrome, and craniotelencephalic dysplasia. Although all of these syndromes are characterized by microphthalmia, the presently reported patient does not have the complete pattern of any of these syndromes, It is possible that he has a previously undescribed syndrome, most closely related to the cerebro-oculo-nasal syndrome with malformations outside the craniofacial region. More case reports are needed to further delineate this possibly new syndrome.