Characterization and localization of myosin in the brush border of intestinal epithelial cells.

The brush border of intestinal epithelial cells consists of a tightly packed array of microvilli, each of which contains a core of actin filaments. It has been postulated that microvillar movements are mediated by myosin interactions in the terminal web with the basal ends of these actin cores (Mooseker, M.S. 1976. J. Cell. Biol. 71:417-433). We report here that two predictions of this model are correct: (a) The brush border contains myosin, and (b) myosin is located in the terminal web. Myosin is isolated in 70 percent purity by solubilization of Triton-treated brush borders in 0.6 M KI, and separation of the components by gel filtration. Most of the remaining contaminants can be removed by precipitation of the myosin at low ionic strength. This yield is approximately 1 mg of myosin/30 mg of solubilized brush border protein. The molecule consists of three subunits with molecular weights of 200,000, 19,000, and 17,000 daltons in a 1:1:1 M ratio. At low ionic strength, the myosin forms small, bipolar filaments with dimensions of 300 X 11nm, that are similar to filaments seen previously in the terminal web of isolated brush borders. Like that of other vertebrate, nonmuscle myosins, the ATPase activity of isolated brush border myosin in 0.6 M KCI is highest with EDTA (1 mumol P(i)/mg-min; 37 degrees C), intermediate with Ca++ (0.4 mumol P(i)/mg-min), and low with Mg++ (0.01 mumol P(i)/mg-min). Actin does not stimulate the Mg-ATPase activity of the isolated enzyme. Antibodies against the rod fragment of human platelet myosin cross-react by immunodiffusion with brush border myosin. Staining of isolated mouse or chicken brush borders with rhodamine-antimyosin demonstrates that myosin is localized exclusively in the terminal web.


Chromosome movement in lysed mitotic cells is inhibited by vanadate.

Mitotic PtK1 cells, lysed at anaphase into a carbowax 20 M Brij 58 solution, continue to move chromosomes toward the spindle poles and to move the spindle poles apart at 50% in vivo rates for 10 min. Chromosome movements can be blocked by adding metabolic inhibitors to the lysis medium and inhibition of movement can be reversed by adding ATP to the medium. Vanadate at micromolar levels reversibly inhibits dynein ATPase activity and movement of demembranated flagella and cilia. It does not affect glycerinated myofibril contraction or myosin ATPase activty at less than millimolar concentrations. Vanadate at 10--100 micron reversibly inhibits anaphase movement of chromosomes and spindle elongation. After lysis in vanadate, spindles lose their fusiform appearance and become more barrel shaped. In vitro microtubule polymerization is insensitive to vanadate.


[Profiles in chronic diseases. I. Investigations of steroid profiles in uremia (author's transl)].

Steroid profiles of hemofiltrates of uremic patients contain as main steroids the sulfates of 11beta-hydroxyetiocholanolone, 11-ketoetiocholanolone, 11beta-hydroxyandrosterone and 11-ketoandrosterone. In blood of uremic patients androstenediol is the main steroid of the sulfate fraction, while in blood of healthy persons dehydroepiandrosterone sulfate is the main steroid. The gradual decrease of the kidney function is characterized by an increase of 11-oxigenated androstane conjugates in urine.


Apparatus to measure flow and sample duodenal contents in calves.

A simple and inexpensive apparatus, requiring minimum labor to operate, was designed to measure flow and sample duodenal contents in young dairy calves. This apparatus simulated normal physiological conditions and was used satisfactorily under varied experimental conditions.


The Lincoln dental caries study: a three-year evaluation of dental caries in persons with various mental disorders.

An evaluation of three-year incremental caries scores in institutionalized persons with various mental disorders indicated that in a DMFS evaluation of caries increment, the group with Down syndrome had significantly fewer caries than many of the other groups compared. No such significant difference was found in an evaluation of DMFT. The caries increments did not differ significantly from one another in all other mentally subnormal groups. The carious lesions in the group with Down syndrome appeared to be limited to the occlusal surface.


The sensitizing potential of periodontal dressings.

The sensitizing potential of three periodontal dressing materials was evaluated by the guinea pig maximization test. The results indicated a difference in the sensitization rate of the three materials.


[Lamellar graft in the treatment of herpes simplex ocular (author's transl)].

72 lamellar grafts for herpes simplex ocular infections have been performed. A retrospective study tries to specify the indications. Penetrating graft is the best for leucomae. The most difficult choice occurs with active herpetic disease. With lamellar grafts good results are obtained in stromal keratitis without deep involvement (visual acuity is 0.2 or more in 75 per cent of cases). When endothelio-uveal involvement, prognosis becomes uncertain in any type of keratoplasty: the authors think that the best method is to perform surgery after a few months of inactive disease.


[Keratoplasty and combined lens extraction in thirty two non traumatic cases (author's transl)].

The combination of two operations seems to have advantages for the patient because it avoids the repetition of surgical intervention. It is indicated, in apparently simple cases consisting of a stable corneal opacity and senile cataract in a normal anterior segment, or on the contrary in complex cases in which the corneal and lens disease has often a common origin, inflammatory, toxic, etc., with the disturbances of the anterior segment. In most cases the anatomical evolution is simple but the functional results often remain modest. In the second cases, the complications are frequent during and after operation and the results are very misleading.


[Corneal oxygen demand: open eye versus closed eye conditions (author's transl)].

Oxygen demands of the mammalian cornea were measured under open eye and closed eye conditions. With the lids gently sealed, oxygen availability to the cornea was found to be about 2/3's that predicted by models in the literature. While the silicone contact lens (0.25 mm thickness) tested under those closed eye conditions still allowed enough oxygen to reach the cornea to just avoid clinically detectable edema, a Hema lens of conventional cosmetic thickness (0.15 mm) would be expected to induce significant edema under those sealed lid circumstances.


[Congenital leukomas with anomalies of the lens migration (author's transl)].

Report of three cases of congenital leukomas with anomalies of the lens migration: first case is an early malformation with "Wedl" cells in the corneal stroma; second case is a Peters' anomaly with ectopic and atrophic lens; third case, with a six years follow up after birthday, shows corneal opacification and regression of the lens. Ultrastructural study of these two last cases.


[Orange pigment and hyperfluorescent pin-point dots on the angiographic datas of malignant melanoma (author's transl)].

In a 65 year old woman, a melanoma has been diagnosed on the following angiographic datas: relief; irregular pigmentation; hyperpigmented border-line; leakage of the dye; orange pigment; hyperfluorescent pin-point dots over the tumor. These last two materials has been histologically studied. It is confirmed that lipofuscin could be the constituant of the orange pigment and that the hyperfluorescent points could correspond with exsudative, hyaline and glyco-lipido-proteic "blebs", in connection with the Bruch's membrane or in the subretinal space. This could be the expression of choriocapillaris and/or RPE suffering.


Histochemistry of rat intrafusal muscle fibers and their motor innervation.

Muscle spindles were followed in serial transverse sections of freshly frozen rat soleus muscles. Adenosine triphosphatase (ATPase) histochemical staining reaction was used to identify nuclear bag1, nuclear bag2 and nuclear chain intrafusal muscle fibers. Regional differences in ATPase staining occurred along bag1 and bag2 fibers but not along chain fibers. Bag1 fibers displayed ultrastructural heterogenity when their intra- and extracapsular regions were compared. Simple "diffuse" and more elaborate "plate" motor nerve terminals were demonstrated histochemically along the poles of bag1 and bag2 fibers by staining for cholinesterase. One motor terminal of the "plate" appearance was present on a chain fiber pole. There was no consistent spatial correlation between the intensity of regional ATPase staining along the nuclear bag fibers and the location, number and type of motor endings. Other factors, such as intrafusal fiber sensory innervation and regional differences in active and passive functional recruitment of nuclear bag fibers during muscle activity, may contribute to the ATPase staining variability along the intrafusal fibers.


[Viral infections of the anterior segment (author's transl)].

A focus on the pathogenesis, clinical manifestations and therapy. Contemporary ideas on viral infections of the anterior segment are examined.--The pathogenesis of lesions (viral activity, delayed hypersensitivity reaction), the clinical aspects of herpes infections of the anterior segment are the result of the relative importance of these two factors. Schematically--dendritic keratitis infiltrates and stromal necrosis and hypopion represent active viral infection. Disciform keratitis, oedematous keratitis, serous iridocyclitis represent delayed hypersensitivity reaction. Corticosteroids are contrindicated in the former cases and recommended in the latter.--Special features concerning zoster inflammations of the anterior segment are considered.--An important number of adenoviral anterior segment infections are also reported and their benign nature stressed.


[Chlorophyllin in choroïdal angiography on rabbit (author's transl)].

The intravenous injection of sodium chlorophyllin carried out on Rabbit leads to the observation of the choroidal vessels and to a complete series of the angiographic times. This technique allows also the use of classical colour slides films.


Overcoming the feeding problems of the mentally and the physically handicapped.

Three centres in the South Manchester area for mentally and physically handicapped children were visited. The paper describes the feeding difficulties of mentally and physically handicapped children and the techniques developed to overcome them, with special reference to the cerebral palsied child. The problems of the adult handicapped person are considered, and the apparatus designed to assist feeding.


Generation of cytotoxic lymphocytes in the autologous mixed lymphocyte culture.

We have studied the ability of purified B lymphocytes to generate cytotoxic T lymphocytes in autologous mixed leukocyte cultures (MLC). Cytotoxic lymphocytes were produced but only autologous mononuclear cells stimulated by lipopolysaccharide (LPS) were susceptible target cells. Unstimulated mononuclear cells and purified B cells were not susceptible to killing by cytotoxic cells generated in the autologous MLC. This suggests that the target antigen may be expressed on stimulated or dividing B lymphocytes in a way that renders the cells more susceptible to cytolysis. Autologously stimulated cytotoxic effector cells were found to exhibit specificity. Cy totoxicity for autologous LPS-stimulated target cells occurred but not for an allogeneic, B cell, histiocytic lymphoma cell line. It is postulated that cytotoxic T cells generated in the autologous MLC may play a role in immune surveillance or in regulation of the immune system.


The effect of T cell growth factor on the generation of cytolytic T cells.

The development of cytotoxic effector cells through primary allogeneic mixed tumor-lymphocyte culture (MTLC) was found to be accompanied by the production of T cell growth factor (TCGF). Addition of supplemental TCGF to MTLC resulted in the generation of significantly greater quantities of effector cells, and these effector cells displayed augmented cytotoxic activity. The TCGF-induced effect could not by duplicated by the addition of fresh medium or a mitogenic concentration of concananvalin A. Although TCGF augmented the proliferation of antigen-nonreactive cells, antigen-reactive cells appeared to be preferentially stimulated by TCGF. Finally, it was shown that depletion of TCGF from MTLC resulted in an impairment of proliferation and differentiation of cytotoxic effector cells. These findings demonstrate that soluble factors are involved in the regulation of in vitro cell-mediated immune responses in an analogous manner to similar factors that have been shown to regulate humoral immune responses. Therefore, the forces affecting TCGF production may modulate the amplitude of a T cell-mediated cytolytic response.


Functional characteristics of BALB/c T cell lines: suppression in the mixed lymphocyte response and cell-mediated lysis.

Previously, 10 BALB/c T cell lines (Thy 1.2+, Ig-) were shown to express different combinations of Ly 1 and Ly 2 antigens. The possible immunologic function(s) of these tumor cells was determined by investigating the effects of these cells on the responses to mitogens, the mixed lymphocyte response (MLR), and the generation of cell-mediated lysis (CML) by normal spleen cells. Five T cell lines, P1798 and BALENTL 3, 5, 8, and 9, continued to synthesize DNA after exposure to large doses of irradiation. Only BALENTL 4, 6, 7, and 14 (Ly 1-(2+)) and BALENTL 13 (Ly 1+(2-)) were radiosensitive and therefore amenable to study. BALENTL 4 and 14 gave significant suppression of the MLR between BALB/c and C57BL/6; BALENTL 14 also inhibited the generation of BALB/c effector cells against C57BL/6 spleen cells. None of these T cell lines had any effect on the proliferative response of BALB/c spleen cells induced by concanavalin A. However, there was approximately 50% suppression of the phytohemagglutinin response of BALB/c spleen cells by BALENTL 14.


Macrophage-T cell interactions in the Con A induction of human suppressive T cells.

Macrophage-T interactions are required for the Con A-induced generation of human Ts capable of inhibiting PHA-induced blastogenesis among autologous PBMC. Con A treatment of adherent cell-depleted PBMC, or PBMC recovered after a 7-day incubation in FCS, failed to generate Ts. Addition of adherent cells to either of these populations restored Con A inducible Ts. Discontinuous density gradient fractionation of adherent cells demonstrated that the required accessory cell was a low density macrophage bearing the human equivalent of murine Ia.


Genetic identification of a locus linked to the rat MHC that codes for a membrane antigen detectable with cytotoxic lymphocytes.

Cell-mediated cytolytic (CMC) responses resulted from immunizations between rat strains purported to be identical at Ag-B, the major histocompatibility complex (MHC), but differing at other loci not linked to Ag-B. In vivo-priming followed by secondary in vitro stimulation was required to generate a measurable CMC response as determined by a 51Cr-release assay. Neither in vivo nor in vitro stimulation alone was adequate. The CMC responses generated in a strain combination considered Ag-B identical (LEW . B3:BN) were specific for a determinant controlled by a gene linked to Ag-B, which has been designated Ag-L. The CMC response appears not to be restricted to sygeneity at Ag-B. In addition, the data presented demonstrate a recombinant between Ag-B and Ag-L, and suggest that the gene has failed to transfer with the MHC during the isolation of the LEW . B3 and F-344 . B3 congenic strains.