Relative DNA contents of somatic nuclei of ox, sheep and goat

Five feeder pigs 4 to 6 months old were orally inoculated with transmissible gastroenteritis virus. Diagnosis of transmissible gastroenteritis was made on the basis of clinical signs and examination of intestinal mucosa by the fluorescent antibody technique. Immunoglobulins were extracted from intestinal fluid of infected feeder pigs. Virus-binding and neutralizing antibodies were detected in intestinal extracts between 7 and 56 days after infection. The concentration of binding antibodies reached a peak at 21 days after infection and was on the decline at the end of the experiment on the 56th postinfection day. In contrast, neutralizing intestinal antibody concentration was increasing on day 56. In both systems, the predominant immunoglobulin was of the IgA class. Examination of blood serums of the pigs by the plaque-reduction technique showed progressive antibody increases ranging in titer from 1:8 on day 7 to 1:256 on day 56 after infection. An analysis of the protein profiles from these serums showed a significant increase in the concentration of gamma-globulins and a decrease in the albumin fraction.     

Biosynthesis and subcellular localization of histamine in H-110 lymphoma

The histidine decarboxylase activity has been studied in the H-110 Lymphoma implanted in Balb-c mice. The enzymatic activity has been determined using DL-Histidine 1-14C by measuring the I--14CO2 liberated during the incubation. It has been found that the histidine decarboxylase activity in the tumor is the highest of the studied tissues. The pretreatment for 5 days with two cytostatic drugs, cyclophosphamide and 5-fluoruracile, determined a decrease of the enzymatic activity in the tumor of 33 and 54 per cent, respectively. This effect has not been observed in the lung. The pretreatment of the animals during 10 days with 0.1 mg per kg body of histamine, which in other experimental tumors induces an increase of the endogenous content of histamine, produces a decrease of the tumoral histidine decarboxylase activity. The histamine-14C uptake was not modified by this pretreatment. The subcellular localization of the radioactivity after pretreatment with histamine-14C evidenced that the nuclear fraction of the tumor contained between 2 and 10 times the radioactivity of other tissues of the same animal.     

A method for the specific labeling of the glycerol in glyceride-containing lipids of Streptococcus faecalis ATCC 9790

Cells of Streptococcus faecalis incorporate radioactive glycerol exclusively into the glycerol moieties of monoglucosyl diglyceride, diglucosyl diglyceride, phosphatidyl diglucosyl diglyceride, phosphatidylglycerol, diphosphatidylglycerol, phosphatidic acid, diglyceride, and a phospholipid tentatively identified as an amino acyl phosphatidylglycerol. Phosphatidylglycerol is one of the major radioactive lipids synthesized and contains an equal amount of radioactivity in each of its two glycerol moieties.