Virus-induced diabetes mellitus. III. Influence of the sex and strain of the host

Nineteen inbred strains of male mice were infected with encephalomyocarditis virus. Five strains became hyperglycemic and had abnormal values in glucose tolerance tests; three strains remained normoglycemic but had abnormal values in glucose tolerance tests; and the remaining strains showed no abnormalities in blood glucose levels or glucose tolerance tests. Female mice from three of five strains tested also developed hyperglycemia, but in one strain (DBA/2) the hyperglycemia was less severe in females than in males. Castrated DBA/2 males developed less severe hyperglycemia than uncastrated males, even though the degree of damage to beta cells appeared to be similar in the two groups. Host factors apparently influence both the development and expression of virus-induced diabetes mellitus.

Using volunteer therapists to reduce hospital readmissions

Two aftercare programs using volunteers as therapists for former inpatients have been effective in reducing hospital readmissions. The volunteer therapists ensure that patients take medications, evaluate them for decompensation, help them find housing and jobs, and give them supportive counseling. In the first program the recidivism rate after one year for 36 chronic schizophrenic women was 11 per cent for the group treated by volunteers and 34 per cent for the control group receiving traditional aftercare. In the second program the recidivism rate after one year for 11 men and women with various types of schizophrenia was 9 per cent for the treatment group and 37 per cent for the control group.

Preparative method for gas chromatographic/mass spectral analysis of trace quantities of pesticides in fish tissue

A large capacity, low efficiency pesticide cleanup method is combined with a small capacity, high efficiency method for gas chromatographic/mass spectral analysis of fish tissue. Trace chemicals are extracted from the tissue, removed from the bulk of the co-extracted lipids through selective desorption from Micro Cel-E, and isolated from the remaining lipids by gel permeation chromatography. The procedure is capable of cleaning up the extract from several hundred grams of fish, minimizes sample contamination, and permits identification of xenobiotic chemicals present at ng/g concentrations.

Iodine-125-labeled antibody to viral antigens: binding to the surface of virus-infected cells

The specific binding of iodine-125-labeled antibody to viral antigens can be used to detect newly synthesized viral antigens and determine the time of appearance of these antigens on the surface of infected cells. Incubation of infected cells with unlabeled antibody to viral antigens specifically blocks the attachment of labeled antibody, and by this inhibition technique the titer of unlabeled antibody to viral antigens can be calculated. The attachment of the labeled antibody to virus-infected cells offers an objective and sensitive method of detecting viral antigens and measuring antibody to virus.

Control of ACh sensitivity by muscle activity in the rat

1. Rat soleus and extensor digitorum longus (EDL) muscles were examined following complete blockade of sciatic nerve impulses with anaesthetics or diphtheria toxin for periods up to 14 days.2. Muscles showed atrophy equivalent to that seen after similar periods of denervation.3. Nerve blockade appeared to have little or no effect on neuromuscular transmission when tested by stimulation beyond the block. Normal spontaneous miniature end-plate potentials were present.4. Nerve impulse blockade caused the entire muscle membrane to become sensitive to iontophoretically applied acetylcholine.5. The increase in sensitivity in soleus could be prevented by chronic nerve stimulation distal to the region of block.6. Tenotomy, of 5-12 days duration, which produced atrophy, had no effect on the sensitivity of soleus to acetylcholine.7. Chronic direct stimulation of denervated soleus or EDL muscles could prevent the usual denervation supersensitivity, or cause it to decline towards normal once it had appeared. However, the sensitivity of the end-plate region remained normal.

Inhibition or enhancement of immunological injury of virus-infected cells

Within hours after infection of cells with herpes simplex, vaccinia, influenza, or Newcastle disease virus, new antigens appeared on the surface of infected cells. The interaction of specific antiviral antibody and complement with these antigens resulted in cell destruction, which was quantitated by the release of (51)Cr. A number of factors can influence the degree of cell destruction, including the density of viral antigens on the surface of infected cells, the nature of the antiviral antibody, and the presence of anti-immunoglobulins. The immunological destruction of virus-infected cells may on the one hand serve as a defense mechanism against certain viral infections, while on the other hand it may contribute to the pathology of the host.