Human granulocyte specific nuclear antigen(s). I: Production of antisera and determination of specificity.

Non-histone protein-DNA complexes isolated from human lung tissue were used to immunize New Zealand rabbits. Quantitative microcomplement fixation and immunocytochemistry revealed a specific chromatin antigen(s) in the human granulocyte nucleus. The study demonstrates the feasibility of employing antisera against chromosomal non-histone protein-DNA complexes for the immunochemical identification of cell types.     

Tandem integration of complete and defective SV40 genomes in mouse-human somatic cell hybrids.

We have analyzed the arrangement of SV40 DNA sequences integrated in human chromosome 7 in two lines of mouse-human somatic cell hybrids: one containing only one human chromosome 7 per cell and the other containing an average of about three. We found that the integration site differs in both the viral and host sequences in the two clones. However, the sites of integration into the several copies of human chromosome 7 of one clone are identical. Each chromosome 7 in both clones carries approximately six viral genomes tandemly linked. Some of these genomes lack about 20% of the DNA from the late region, including the Eco RI site.     

Splenic Subcapsular Hematoma—Ultrasonic Diagnosis

In five patients with varying histories of blunt abdominal trauma, examinations were carried out with ultrasonography and other imaging modalities. In all five patients, large, fluid-filled masses were noted in the left upper quadrant. Two patients had nonpalpable hematomas, but examinations were done because of history and vague clinical symptoms. Three patients had palpable masses. In all five patients there was surgical confirmation of the ultrasonic findings, and all recovered without complications. Ultrasonic tomography offers a convenient noninvasive method for assessing suspected splenic hematoma and can also exclude the possibility in a careful examination.     

Death on Denali: Fatalities Among Climbers in Mount McKinley National Park From 1903 to 1976—Analysis of Injuries,Illnesses and Rescues in 1976

Between 1903 and 1975 about 1 percent of climbers on Mount McKinley (Denali) and Mount Foraker in Alaska died. In 1976 a total of ten (1.7 percent) of 587 mountaineers died, but this rate of death was not significantly higher than previously.Nineteen percent of climbers in 1976 suffered major or minor injuries, illness or death. Acute mountain sickness (AMS), frostbite and fractures were common. Thirty-three rescues or retrievals of bodies were mounted at a cost of more than $82,000.Inexperience (particularly with arctic mountaineering), poor leadership, faulty equipment and undue reliance on rescue by helicopter contributed to the alarming incidence of accident, illness and death on big peaks in Mount McKinley National Park in 1976.     

Lipochondria and the light response of Aplysia giant neurons

The ultrastructure, absorbance, and elemental content of lipochondria present in the cytoplasm of Aplysia giant neurons have been investigated before and after 30–1,200 sec doses of white light at intensities which produce saturated light responses. The effects of exposure to the calcium ionophore A-23187 and to EGTA were also examined. The lipochondria of nonilluminated neurons are membrane-bound, and contain lipids, protein, Na, K, Mg, Ca, Si, Cl, Br, P, and a pigment which is probably β-carotene. The cytoplasm appeared to have little pigment. When neurons were illuminated for 20 min, 60–70% of the lipochondria showed marked ultrastructural alterations, the most notable being the appearance of membranous material. Earlier changes which occur after 30 sec of illumination include the appearance of paracrystalline arrays and mottling. Less than 10% of lipochondria in nonilluminated neurons have a similar appearance. These effects were greatly enhanced in illuminated neurons exposed to the calcium ionophore or EGTA. In nonilluminated neurons, the ionophore also produced ultrastructural changes. In frozen specimens, the calcium content of the most electron dense lipochondria of illuminated neurons was reduced. Other elements which were counted were also reduced. The lipochondria are the main intracellular site of photopigment. They may also act as an intracellular source for calcium which, as the accompanying paper indicated, may mediate phototransduction in Aplysia neurons.     

Pseudomonas aeruginosa colonisation in an intensive therapy unit: role of cross infection and host factors.

Despite the sparsity of Pseudomonas aeruginosa in the environment colonisation and infection with this organism was found at several sites by selective culture in 20 out of 46 patients in an intensive therapy unit. Three patients developed Ps aeruginosa pneumonia. Serial serogrouping and phage typing identified multiple strains in the unit and in the same patient. Rectal carriage occurred in 16 patients but rectal strains did not subsequently appear in tracheal aspirates; strains varied in their affinity for the upper respiratory tract. Colonisation was not directly related to length of stay and was detected in 16 of those colonised within 24 hours of admission. In intubated patients, who were colonised more frequently than those not intubated, upper respiratory tract colonisation correlated strongly with low initial arterial pH values. Personnel were probably responsible for cross infection among patients when the unit was busy. Strain differences and the susceptibility of patients also influenced colonisation and infection. Elimination of major reservoirs of Ps aeruginosa and compliance with procedures to control cross infection remain essential if patients in hospital are to escape colonisation by the organism.     

Immunosuppressive properties of leukotriene D4 and E4 in vitro

Leukotrienes D₄ and E₄ whose physiological function has been associated with smooth muscle contraction, are demonstrated to be potent suppressors of immunocompetent cell function. In concentrations as low as 10^?12 M both leukotriene D₄ and E₄ can inhibit mitogen-induced lymphocyte transformation. Higher concentrations of leukotrienes E₄ and D₄ will inhibit appearance of antibody-forming cells in tissue culture. These data suggest another role for the leukotrienes in addition to their function as slow-reacting substances.     

Suppression of B-cell and T-cell responses by the prostaglandin-induced T-cell-derived suppressor (PITS). I. Analysis of the PITS beta factor

Within populations of mitogenically (PWM) stimulated normal human lymphocytes, the proliferation of B lymphocytes is terminated by T cells. In contrast, T cells limit their own proliferation. T cells thus apparently measure and terminate the proliferation of B cells as well as themselves, suggesting an important role for them in limiting amplification during immune response. Under the culture conditions employed, PWM-induced B- and T-cell proliferation was uncoupled from B-cell differentiation into plasmacytes. Termination of B-cell proliferation in this in vitro model of humoral immune response is independent of B-cell differentiation.     

Muscle spindle formation and differentiation in regenerating rat muscle grafts

Muscle spindle development and function are dependent upon sensory innervation. During muscle regeneration, both neural and muscular components of spindles degenerate and it is not known whether reinnervation of a regenerating muscle results in reestablishment of proper neuromuscular relationships within spindles or whether sensory neurons may exert an influence upon differentiation of these spindles. Muscle spindle regeneration was studied in bupivacaine-treated grafts of rat extensor digitorum longus (EDL) muscles. Three types of EDL graft were performed in order to manipulate the extent to which regenerating spindles might be reinnervated: (1) grafts reinnervated following severance of their nerve supply (standard grafts); (2) grafts in which intact nerve sheaths appear to facilitate reinnervation (nerveintact grafts); and (3) grafts in which reinnervation was prevented (nonreinnervated grafts). Complete degeneration of muscle fibers occurred in all grafts prior to regeneration. Initial formation of spindles in regenerating EDL grafts is independent of innervation; intrafusal muscle fibers degenerate and regenerate within spindle capsules that remain intact and viable. The extent of spindle differentiation was evaluated in each type of graft using criteria that included nucleation and ATPase activity, both of which have been shown to be regulated by sensory innervation, as well as the number of muscle fibers/spindle and morphology of spindle capsules.While most spindles contained normal numbers of muscle fibers, most of these fibers were morphologically and histochemically abnormal. Alterations of ATPase activity occurred in all spindles, but were least severe in nerve-intact grafts. While fully differentiated nuclear bag and chain fibers were not observed in regenerated spindles, large, vesicular nuclei, similar to those of normal intrafusal fibers, were present in a small number of spindles in nerve-intact grafts. Sensory nerve terminations were observed only in those spindles that also contained the distinctive nuclei. This study suggests that a specific neurotrophic influence is necessary for regeneration of normal intrafusal muscle fibers and that this influence corresponds to the properly timed sensory neuron-muscle interaction which directs muscle spindle embryogenesis. However, the infrequent occurrence of characteristics unique to intrafusal muscle fibers indicates that reinnervation of regenerating muscle grafts by sensory neurons is inadequate and/or faulty.