Antigen-induced lymphomagenesis: identification of a murine B cell lymphoma with known antigen specificity

CH12, a murine B cell lymphoma derived in B10 H-2aH-4bp/Wts mice after transfer of SRBC hyperimmunized spleen cells into an adult-thymectomized, sublethally irradiated, syngeneic recipient, is demonstrated to bear surface IgM specific for a determinant found on SRBC and ChRBC. The Ig specificity has been demonstrated by rosetting assays and complement-dependent hemolysis. The removal of CH12 surface IgM by capping with anti-mu or with anti-CH12 idiotype, but not with anti-gamma or with irrelevant anti-idiotype, eliminated the formation of rosettes between CH12 and SRBC or ChRBC. The absorption of CH12 Ig produced in vitro, with either SRBC or ChRBC but not with HRBC, removed all hemolysin activity against SRBC, demonstrating that only one CH12 product was responsible for the reactivity with both SRBC and ChRBC. CH12 has a surface phenotype of a relatively mature B cell expressing surface Ig (IgM-mu,kappa) and la antigens, but lacking Thy-1 or detectable Fc or C3 receptors. CH12 also expresses the antigen Lyt-1. Growth of CH12 in vivo or in vitro results in the generation of up to 3% direct PFC and serum hemolysin, which shows that CH12 is not irretrievably "frozen". The generation of PFC and serum hemolysin is associated with increased population density, and the rate of PFC and serum hemolysin accumulation cannot be explained by simple cell division. A continuously secreting hybridoma derived from CH12 was used to purify the CH12 IgM to facilitate studies of protein sequence and idiotype.     

Correction of lower eyelid ptosis in the anophthalmic orbit: a long-term follow-up

We describe a 10-year review of 53 patients having had correction of lower eyelid ptosis using fascia lata sling suspension by the operation first described in 1973. The overall conclusion is that this continues to be a reliable procedure with a low complication rate. Four major changes relating to operative technique that create a better result are as follows: (1) the surgical correction must begin with a prosthesis that is ideal for the socket; (2) the fascial strip is narrower at 2 mm; (3) the lateral orbital rim burr hole is placed higher; and (4) the passage of the fascial strip is facilitated by the use of Wright's needle. The optimal sequence of operative procedures in the anophthalmic orbit syndrome is (1) correction of enophthalmos and superior sulcus depression, (2) correction of lower eyelid ptosis, and (3) correction of upper eyelid ptosis.     

Breast reconstruction by superior gluteal microvascular free flaps without silicone implants

The author's experience with 10 gluteus maximus myodermal free flap breast reconstructions is reviewed against the current methods of reconstruction using silicone implants, latissimus dorsi flaps, regional skin flaps, and rectus abdominis myodermal flaps. The superior gluteal free flap can achieve a reliable, permanent, and aesthetic reconstruction of the breast without silicone implants. The softness, projection, natural appearance, and patient satisfaction are excellent compared with other methods. It is particularly useful in patients who object to the use of artificial implants, are not suitable for regional flaps, or have disappointing results from previous reconstructions. Technical modifications of the flap design and selection of the recipient vessels are important.     

Relationship of seminal vesicle size and measures of libido in yearling beef bulls

Ninety-five yearling beef bulls were given routine Breeding Soundness Examinations, two libido tests and palpated rectally for internal genital disease and measurement of seminal vesicle size. Finger tips were premeasured, and then used as "glandometers". The bulls were examined at the end of a 140-day performance test. Sixteen lines of breeding were examined including 13 Hereford, 2 Angus and 1 Red Angus. Average age was 384 days and average weight was 961 lbs. Line and breed differences (P<.05) were observed for scrotal circumference, scrotal circumference score and second libido test. Similar differences were observed for SV length (P<.01), depth and volume both (P<.05). There were no significant correlations between seminal vesicle (SV) size and libido scores. There were, however, significant correlations between SV size and scrotal circumference (P<.05), BSE score (P<.01), body weight (P<.01), and semen morphology score (P<.05). Proximal droplets and midpiece abnormalities, respectively, were the most common spermatozoal abnormalities observed in semen from this group of bulls.     

Dictyostelium mutants lacking DIF,a putative morphogen

DIF is an endogenous extracellular signal that may control differentiation of D. discoideum cells. It is a dialyzable, lipid-like factor that induces stalk cell formation among isolated amebae incubated in vitro with cAMP. To examine the consequences of DIF deprivation, we have isolated several mutant strains that are impaired in DIF accumulation, and whose inability to make stalk cells in vitro and during normal development on agar can be corrected by the addition of exogenous DIF. Little DIF is made by the mutants, and morphological development on agar stops after the cells have aggregated, but before a slug forms. In these DIF-deprived conditions, prespore cells can differentiate, but prestalk cells cannot.     

Influenza virus hemagglutinin expression is polarized in cells infected with recombinant SV40 viruses carrying cloned hemagglutinin DNA

Primary cell cultures of African Green monkey kidney (AGMK) contain polarized epithelial cells in which influenza virus matures predominantly at the apical surfaces above tight junctions. Influenza virus glycoproteins were found to be localized at the same membrane domain from which the virus budded. When polarized primary AGMK cells were infected with recombinant SV40 viruses containing DNA coding for either an influenza virus H1 or H2 subtype hemagglutinin (HA), the HA proteins were preferentially expressed at the apical surface in a manner identical to that observed in influenza virus-infected cells. Thus, cellular mechanisms for sorting membrane glycoproteins recognize some structural feature of the HA glycoprotein itself, and other viral proteins are not necessary for this process.     

Generation of asymmetry and segregation of germ-line granules in early C. elegans embryos

Germ-line granules in C. elegans embryos (P granules) can be visualized by immunofluorescence microscopy using a monoclonal antibody. In mutant zygotes with abnormal spindle orientations and in wild-type zygotes treated with the microtubule inhibitors nocodazole, colcemid, vinblastine, and griseofulvin, both P-granule segregation to the posterior pole and the concomitant pseudocleavage occur apparently normally, but the normally concurrent migration of the pronuclei is inhibited. Conversely, treatment of wild-type embryos with the microfilament inhibitors cytochalasins D and B inhibits P-granule segregation and pseudocleavage, as well as other manifestations of polarity, without preventing pronuclear migration. The results suggest that P-granule segregation does not require either the spindle or cytoplasmic microtubules, but that this process as well as generation of other asymmetries does require cytoskeletal functions that depend on microfilaments.