Purification and characterization of stage-specific glycoproteins from Trypanosoma cruzi

Four developmentally regulated glycoproteins were purified from detergent solubilized cell membranes of Trypanosoma cruzi. Three trypomastigote specific glycoproteins each migrated as single bands under denaturing conditions with approximate Mr of 90,000, 85,000, and 55,000 and pI values of 4.3-5.0, 8.5-9.1, and 8.2, respectively. The fourth, epimastigote specific, protein had an approximate Mr of 72,000 and a pI of 4.8-5.1. The Mr of all four glycoproteins changed by 5-50% upon endoglycosidase F treatment. The Mr 72,000 antigen was the only one that reacted strongly with anti-epimastigote sera raised in rabbits. Sera from a Chagasic patient reacted strongly with the three trypomastigote specific glycoproteins and very weakly with the Mr 72,000 glycoprotein.     

HEAD INJURIES IN A GENERAL SURGICAL UNIT

A five years' experience of the care by general surgeons of patients with severe head injuries in a general surgical unit with inferior facilities was retrospectively reviewed. It was concluded that the mortality compared favourably with that in similar patients managed by neurosurgeons in specialized centres. The still inadequate understanding of primary diffuse brain damage in head injuries is suggested as the cause for this lack of significant improvement in results over the years. Certain guide-lines, however, exist to allow prediction of the eventual outcome in these patients.     

Rapid immunoperoxidase staining of axons for frozen section diagnosis of nerve biopsy specimens.

A new method of freezing and embedding a nerve biopsy specimen and staining it with the immunoperoxidase technique for neurofilaments was developed to overcome the difficulties normally encountered in the assessment of tiny portions of nerve. The method clearly shows the architecture of the nerve, the exact number and size of all axons present, and the degree of fibrosis present. The entire procedure may be accomplished in 20 minutes.     

Dietary restriction, cell proliferation and carcinogenesis: a preliminary study

Four groups of female Swiss Webster mice were given either laboratory chow or a purified (semi-synthetic) diet (AIN-76A) either ad libitum or at 75% of the ad libitum rate for about 30 days. Three tissues, the crypt cells of the jejunum, the dermis and the basal epithelial cells of the esophagus were investigated using [3H]thymidine labelling and by counting mitoses; four other tissues, the alveolar cells of the mammary gland, the crypt cells of the duodenum and colo-rectum, and the transitional cells of the urinary bladder were examined using [3H]thymidine labelling only. In each case dietary restriction led to a reduction of cellular proliferation assessed by these indices. The potential of the approach for the study of the effects of dietary modification on the induction of cancer is discussed.     

Detection of antimitochondrial antibodies by immunodiffusion, ELISA and immunofluorescence methods

Ouchterlony immunodiffusion and ELISA were used for the detection of antimitochondrial antibodies. The results were compared with those of immunofluorescence measurements. The occurrence of antimitochondrial antibodies was investigated in 20 patients with primary biliary cirrhosis, in 30 with autoimmune disease and in 28 with porphyria cutanea tarda. Sonicated rat liver mitochondria fractions were used as antigens. Among the patients with primary biliary cirrhosis, Ouchterlony immunodiffusion revealed antimitochondrial antibodies in 18 cases, whereas antibodies were not found in the other groups of patients, except for 1 case of systemic lupus erythematodes. ELISA demonstrated that in all 20 patients with primary biliary cirrhosis where immunofluorescence revealed antimitochondrial antibodies, there was an increase in the quantity of antibodies against mitochondrial inner membrane fractions, and in 7 cases even against the outer membrane fractions. These 7 were the most serious cases clinically. These methods allow the differentiation of antimitochondrial antibody subtypes and promote the establishment of the diagnosis.