Electron microscopic studies of the DNA of defective and standard pseudorabies virions.

DNA from standard and defective virus particles was analyzed by electron microscopy. Upon partial denaturation the DNA molecules from standard pseudorabies virus showed distinct denaturation patterns. The molecules are asymmetrical with respect to adenine-thymidine (A-T) content, having several A-T-rich regions on the “left” side and only one on the “right” side of the molecule. The fact that a distinct denaturation map was obtained indicates that the molecules are not circularly permuted. On the extreme left of the molecule a segment of approximately 0.5 μm invariably contained denatured regions, whereas this was not evident on the right side of the molecule. Thus, if the molecule is terminally redundant, the redundant region covers a relatively small part of the viral genome. The contour length of the DNA molecules present in defective, interfering particles was found to be similar to that of standard DNA. Under partial denaturation conditions a distinct segment of DNA (1.1 μm in length) was found to be tandemly repeated in defective DNA. The number of repeats in different molecules varied. In some of the DNA molecules as many as 17 consecutive repeats were found, whereas in others no repeats were seen. Repeated segments were not detected in standard DNA.     

Freeze Dried Platelets for HLA Alloantibodies Absorption

Antibodies to HLA–A and B are specifically absorbed onto platelets. A method of absorption of these antibodies using freeze dried platelets is described. This method allows long-term storage and standardized absorption procedures. Anti-DR antibodies and cold lymphocytotoxins are recovered in the supernatant.     

First reported case of streptococcus pyogenes infection with toxic shock-like syndrome in Italy

A 43-year-old male who sustained a superficial hand injury developed streptococcal toxic shock-like syndrome and died within 48 hours. The clinical course of the illness in this previously well patient was rapid and fulminant. The organism responsible was a group A beta-hemolytic streptococcus which was identified as opacity factor negative, M serotype 1, T type 1. The organism produced streptococcal pyrogenic exotoxins B and C, but no detectable exotoxin A although it carriedspeA, the gene for exotoxin A. This is the first case reported in Italy, and further emphasizes the virulence of these organisms and the rapidity with which the illness can progress.     

Micropurification techniques in the analysis of amyloid proteins

This review describes the different microtechniques developed for the extraction and purification of amyloid proteins from small specimens of fresh and formalin fixed tissues. These procedures differ with respect to solvent type, extraction conditions, and protein purification strategy. The advantages and disadvantages of the different microtechniques are discussed by taking into consideration tissue type (fresh of fixed) and size, amyloid type, and its content in the tissue. The review demonstrates the applicability of these techniques for the immunochemical and chemical characterisation of amyloid in different clinical forms of amyloidosis and in experimental small animal models. The clinical value of the applied microtechniques and their importance in the study of the pathogenesis of amyloid related diseases are outlined.     

Neuromuscular organization of the pectoralis (pars thoracicus) of the pigeon (Columba livia): implications for motor control

The pectoralis (pars thoracicus) of the domestic pigeon (Columba livia) is divisible into two anatomical parts, the pars sternobrachialis (SB) and the pars thoracobrachialis (TB). Innervation to this complex is from rostral and caudal branches of the brachial ventral cord. In four anesthetized pigeons, the distribution of muscle units associated with each nerve branch was mapped after prolonged stimulation of each nerve and subsequent analysis for muscle fiber glycogen. An additional three animals were used to analyze the morphology, distribution, and histochemical profiles of the muscle fibers in the SB and TB subregions. Fibers were characterized on the basis of their reactions for myofibrillar adenosine triphosphates (alkaline and acid preincubation) and reduced nicotinamide adenine dinucleotide diaphorase (NADH-D). The SB is primarily innervated by the rostral nerve branch and the TB by the caudal nerve branch. For two-thirds of the muscle's length, the SB is separated from the TB by an aponeurosis, the membrana intermuscularis (MI). SB and TB fibers located posteroventral to the caudal margin of the MI are innervated variously by both nerves. Two populations of fibers were recognized, distinguishable primarily by 1) fiber diameter and 2) density of the NADH-D reaction product. Compared to the TB, the SB possesses a higher average percentage of large fibers. Within the SB but not the TB the percentage of large fibers increases from deep to superficial. These data support our previous findings that the pars thoracicus of the pigeon is partitioned into at least two functional subunits, each with a potential for independent action on the wing during flight.     

The effects of separation and reunion on the behavior of mother and infant squirrel monkeys

Mother and infant squirrel monkeys that lived together in a socially restricted environment were separated for a period of seven days after the infants had become relatively independent, and were then reunited. Behavioral observations before, during, and after separation indicated that (1) female infants became independent of their mothers earlier than males, (2) neither mothers nor infants were severely affected by separation, and (3) an increase in attachment occurred following reunion only when the mother had a limited history of maternal experience. These results suggest that (1) certain characteristics in the maternal behavior of the squirrel monkey facilitate readjustment in mothers and infants following maternal separation, (2) maternal experience can influence the mother-infant relationship following a period of separation, and (3) the independence of infants from their mothers may be a function of both sex and species.     

Human polymorphonuclear leukocyte interaction with cyclosporine A.

The effects of cyclosporin A (cyA) on human polymorphonuclear leukocyte function, including phagocytosis, its associated metabolic burst, bacterial killing, and chemotaxis, were evaluated. Both Pseudomonas aeruginosa and Staphylococcus aureus were used as test particles. Polymorphonuclear leukocytes incubated in 10 and 50 micrograms of cyA per ml behaved normally with respect to phagocytosis and hexose monophosphate shunt activity at both high (10:1) and low (2:1) S. aureus/leukocyte ratios. With a small bacterial inoculum, killing of S. aureus was slightly impaired at early times only in the presence of 50 micrograms of cyA per ml. Phagocytosis and killing of P. aeruginosa with both large and small bacterial inocula were unaffected by cyA. Chemotaxis was within normal limits under all conditions. In addition, polymorphonuclear leukocytes from four renal transplant recipients receiving both cyA and prednisone demonstrated normal metabolic bursts and bacterial killing with both small and large inocula of S. aureus.     

Differences in the mother-infant relations of squirrel monkeys housed in social and restricted environments

Mother and infant squirrel monkeys were housed together in either a group or a restricted environment until the infants were approximately 22 weeks of age. Observations of the mothers' and infants' behavior during this period revealed clear differences between the rearing conditions. Mothers in the socially restricted environment avoided and punished their infants more and were generally less protective than those in the group environment. However, these differences did not appear to reflect differences in maternal attitudes per se, but rather the extent to which infants in the two environments engaged in certain activities. Infants in the restricted environment attempted to play with their mother more often and remained closer to her as they became older.