Role of prostaglandins in pathogenesis of bovine mastitis induced by Escherichia coli endotoxin

Four doses (5 to 100 micrograms, 1 dose/quarter) of Escherichia coli endotoxin were introduced into lactating mammary glands of 2 cows. There was no effect on milk prostaglandin (PG) E2 concentration, except that the concentration was increased from 200 pg/ml of milk to 1,060 pg/ml at post-treatment hour (PTH) 8 in cow 1 and from 75 to 420 pg/ml at PTH 4 in cow 2 after the highest dose 100 micrograms. Endotoxin caused a dose-dependent increase in milk PGF2 alpha concentrations in both cows. After the highest dose, PGF2 alpha was maximally increased from 200 to 3,500 pg/ml at PTH 4 in cow 1 and from 250 to 2,000 pg/ml in cow 2 at PTH 8. The instillation of 50 micrograms of endotoxin in all 8 quarters of 2 more lactating cows caused no significant (P greater than 0.05) changes in milk PGE2 and thromboxane B2 concentrations, whereas milk PGF2 alpha was significantly increased from the base-line value of 642 to 2,683, 1,189, and 2,281 pg/ml at PTH 4, 8, and 12, respectively. The 6-keto-PGF1 alpha was also significantly increased from the base-line value of 305 to 871, 631, and 600 pg/ml at the corresponding times, respectively. A marked increase in vascular permeability, as judged by high concentrations of serum albumin in the whey, was observed as early as PTH 4 and peaked at PTH 12 followed by a gradual decline, although it remained significantly increased over the control for 48 hours after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Membrane proteins unique to vertebrate olfactory cilia: candidates for sensory receptor molecules

In search for olfactory receptor molecules, we carried out comprehensive electrophoretic mapping of membrane proteins in the cilia of frog olfactory epithelium. Seven polypeptides, extracted from isolated cilia by nonionic detergent, were unique to the sensory organelles, compared to nonsensory (respiratory) counterparts. Olfactory cilia contained 3-10 times more membrane-associated protein as compared to respiratory cilia, in agreement with reported densities of freeze-fracture intramembranous particles. Four of the olfactory polypeptides were major constituents of the ciliary membrane, each amounting to greater than 10% of its total protein. Three major and one minor specific polypeptide were glycosylated, whereas membranes of nonsensory cilia were practically devoid of glycoproteins. A clear difference in surface composition was also shown by microscopic visualization of fluoresceinated lectin bound to intact isolated cilia. Two of the olfactory glycoproteins displayed pronounced heterogeneity of apparent molecular weight, which could partly be due to protein sequence diversity, as expected for odorant receptor molecules. The recently described inhibition of odorant-evoked sensory potentials by the lectin concanavalin A is consistent with the hypothesis that one or more of the specific glycoproteins described here plays a role in olfactory reception.

Ameloblastoma of the mandible treated by resection, preservation of the inferior alveolar nerve, and bone grafting

The results of five cases of ameloblastoma of the mandible treated by resection, preservation of the inferior alveolar nerve, and immediate bone grafting are reported. The incisions in all cases healed by first intention. Lip sensation on the operated side returned to normal in four to six weeks in four cases and slight numbness persisted to the eighth week in one case. All patients were followed postoperatively for 13-15 years. In one case the tumor recurred in the mucous membrane seven years after surgery at the original intraoral site and invaded the underlying bone graft. The indications and contraindications for surgery and details of the procedures, including measures to prevent recurrence, are presented.

3AE8: monoclonal antibody defining inflammatory macrophages in three species

A mouse monoclonal antibody (MAb 3AE8) of the IgG1 isotype was prepared against rabbit splenocytes and was found by indirect immunofluorescence and direct binding assays to react, in the rabbit, primarily with oil-induced peritoneal exudate macrophages (PEM phi). This MAb did not bind to rabbit T cells, B cells, polymorphonuclear leukocytes, or resident alveolar or peritoneal M phi but it did bind to a subpopulation of rabbit splenocytes with surface characteristics of null cells. The antibody also recognized mouse and rat PEM phi as well as the murine M phi cell lines P388D1 and IC-21. Consistent with findings in the rabbit, it did not bind to M phi obtained from the peritoneal cavities of rats or mice. The addition of MAb 3AE8 to mouse PEM phi caused a marked enhancement in the phagocytic uptake of erythrocyte target cells sensitized with a mouse antierythrocyte antiserum.

Cerebral response to medullary pyramid stimulation in the rabbit

The response evoked in the cerebral cortex of the rabbit by stimulation of the medullary pyramid was studied electrophysiologically. The response was everywhere surface-positive and began 2-3 ms after the stimulus. It exceeded 1 mV in amplitude and generally lasted 2-4 ms. Maps of the response showed it to extend throughout the anterior one-third of the cortex (in the 'motor' cortex) and into adjacent tissue, including the limbic cortex. Although it depended on antidromic conduction in pyramidal tract fibers for its production, it varied in amplitude, configuration and latency at different sites and at the same sites on repeated trials. It was found to reverse polarity deep in the cortex, to become a large, negative wave in layer V and to maintain that polarity into the underlying white matter. The response disappeared during a spreading depression, though it recovered more rapidly than the primary response evoked by skin stimulation. Maps of the primary response showed a strong overlap with the 'antidromic' response, though the response was largest slightly caudal to the maximal focus of the 'antidromic' response and extended more caudally through transitional and into limbic cortex. The 'antidromic' response showed two major foci on the cortex, with an additional minor focus located more laterally. It is argued that the 'antidromic' response in the rabbit is the same as that found in the opossum, woodchuck, rat and slow loris, and is markedly different from that found in the cat and macaque monkey. It is postulated that this response reflects synaptic action in pyramidal tract axon collaterals, probably onto cell bodies in layer V, rather than being a purely antidromic event.

Gm allotypes in blacks with systemic lupus erythematosus

Serum samples were collected from 328 healthy American Blacks and from 61 American Blacks with systemic lupus erythematosus (SLE). Sera were typed for the Gm1,2,3,5,6,13,17, and 21 allotypes as well as for the Km(1) allotype. The frequency of Gm phenotype 1,17;5,6,13 was significantly increased in the SLE patients (p = 0.0001, RR = 3.19, EF = 0.29). Our data suggest the existence of at least two immunoglobulin allotype associated genes that somehow interact to increase susceptibility to SLE in Blacks. To our knowledge, this is the first report of an association of Gm and SLE in Blacks.

Effect of strychnine on the cutaneous responsiveness of wide-field cerebral neurons after depression by pentobarbital

A small dose of pentobarbital administered intravenously to a chloralose-anesthetized cat rendered pericruciate wide-field neurons unresponsive to cutaneous stimulation without altering the responsiveness of small-field neurons. Under this condition, topical application of strychnine, which is known to markedly enhance the responses of small-field neurons, was found to restore the responsiveness of the wide-field neurons, but only to stimulation of the topographically focal cutaneous site. Wide-field responsiveness returned only after the effect of pentobarbital had disappeared and the cortex returned to its normal chloralose condition. This result is consistent with the idea that small-field neurons have excitatory synaptic connections with the wide-field neurons in their immediate neighborhood.

Further evidence for T cell abnormalities in chronic lymphocytic leukaemia of the B cell type

Functional properties were studied in the purified T cell fraction of patients with chronic lymphocytic leukaemia of the B cell type (B-CLL). This analysis included the evaluation of T suppressor activity when investigated patients' T cells were co-cultured together with allogenic normal B and OKT4 enriched T cells in the presence of pokeweed mitogen (PWM). The Ig secreting cells (ISC) were assessed in a reverse haemolytic plaque assay (RHPA). Antibody-dependent cytotoxicity (ADCC) and natural killer activity (NK) were determined in a 51Cr release assay. Furthermore, purified T cells reactive with the monoclonal antibody HNK1, known to recognize most effector cells in ADCC and NK, were enumerated using an indirect immunofluorescence. Our results revealed increased T suppressor cell activity and markedly deficient NK activity in peripheral blood lymphocytes (PBL), T cell and T gamma cell fractions from B-CLL patients, whereas ADCC potential was only increased in T cells and T gamma cells. Accordingly, T cells were recognized by HNK1 in greater numbers in B-CLL patients than in healthy subjects. Our data suggest that there may be a link between our findings and the hypogammaglobulinaemia as well as the increased incidence of second neoplasias reported in CLL.

The in vitro synthesis and degradation of prostaglandins during the development of bleomycin-induced pulmonary fibrosis in hamsters

Subsequent to optimization of conditions for enzyme assay, we examined the in vitro synthesis and degradation of prostaglandins by the lung during the development of bleomycin-induced pulmonary fibrosis in hamsters. It was found that the microsomal protein content on a per lung basis was significantly increased to 144, 129, 134, and 121% of control (2.3 mg protein/lung) at 4, 7, 14 and 21 days post-treatment, respectively. The synthesis of PGD2 was significantly elevated to 10.2, 10.8, and 12.5 nmoles/lung at 7, 21 and 28 days, respectively, as compared to the control value of 5.6 nmoles/lung. Significant increases in PGF2 alpha synthesis from the control value of 3.3 nmoles/lung to 5.2, 8.2 and 5.5 nmoles/lung were found at 4, 7 and 21 days post-treatment, respectively. The synthesis of PGE2 also showed significant increases above the control value of 6.1 nmoles/lung to 10.5, 12.2 and 11.0 nmoles/lung at 7, 21 and 28 days post-treatment, respectively. Similarly, the synthesis of 6-keto-PGF1 alpha was significantly increased to 7.4, 7.5 and 8.6 nmoles/lung at 7, 21 and 28 days post-treatment, respectively, as compared to the control value of 4.4 nmoles/lung. The synthesis of TxB2 was also significantly increased from the control value of 3.9 nmoles/lung to 7.5 and 6.4 nmoles/lung at 7 and 21 days post-treatment, respectively. Accompanying the increased synthesis of prostaglandins in general, the in vitro degradation of PGF2 alpha was significantly increased from the control value of 71.1 nmoles/lung to 173.5, 131.7 and 143.3 nmoles/lung at 2, 4 and 7 days after bleomycin treatment, respectively. We conclude that bleomycin-induced pulmonary fibrosis leads to changes in prostaglandin synthesis and degradation possibly as a result of an accompanying inflammatory response and resident cellular proliferation.

Erythroleukemia cells: variants inducible for hemoglobin synthesis without commitment to terminal cell division

Murine erythroleukemia cells (MELC) are virus-transformed erythroid precursors that appear to be blocked at an erythroid precursor stage comparable to the erythroid colony-forming unit (CFU-e). These cells are useful in examining factors regulating terminal differentiation. Induced MELC are characterized by a coordinated program of gene expression, including commitment to terminal cell division, accumulation of globin mRNAs and corresponding hemoglobins, and accumulation of several other proteins, including the chromatin-associated protein H1(0). Two cloned variant cell lines, DR10 and R1, have been developed from inducer-sensitive DS19 cells by selection for inducer resistance. DR10 and R1 cells fail to display commitment to terminal cell division when cultured with dimethyl sulfoxide (Me2SO), hexamethylene bisacetamide (HMBA), or butyric acid. Both cell lines are induced by all three agents to accumulate H1(0). DR10 cells are resistant to Me2SO-mediated accumulation of hemoglobin but are sensitive to HMBA- or butyric acid-mediated accumulation. R1 cells are resistant to Me2SO- and HMBA-mediated accumulation of hemoglobin but are sensitive to butyric acid-mediated accumulation. Both DR10 and R1 are commitment-negative MELC variants, displaying variable responses to inducers with respect to other features of terminal erythroid cell differentiation.

Recent advances in anther culture of Hevea brasiliensis (Muell.-Arg.)

The yield of pollen embryoids from cultured Hevea anthers was increased 4 fold by optimizing the proportion of ammonium nitrate to potassium nitrate in the dedifferentiation medium. For optimal differentiation of pollen embryoids, kinetin, 2,4-D and α-naphtalene acetic acid are required. Anther culture for 50 days on the dedifferentiation medium is a prerequisite for the selective development of calli and embryoids from microspores.The determination of chromosome numbers in embryoids, plantlets and regenerated trees reveals that they originate from (poly)haploid pollen grains (n=2x=18). Aneuploid, triploid (3x=27) and tetraploid (4x=36) cells were encountered in increasing frequencies as the embryoids and plants developed. A few haploid cells with 9 chromosomes were consistently observed. Buds from shoots with mixoploid chromosome numbers can be grafted and the change in the chromosome constitution of the developing new shoots followed.

Inducer-mediated commitment of murine erythroleukemia cells to differentiation: a multistep process

There are a number of agents which, when added to cultures of murine erythroleukemia cells (MELC), markedly increase the probability of commitment to express the characteristics of terminal erythroid differentiation, including loss of proliferative capacity and increased accumulation of globin mRNA and hemoglobin. Some characteristics of inducer-mediated commitment of MELC to terminal erythroid differentiation were examined by determining the effects of dexamethasone (an inhibitor of inducer-mediated MELC differentiation) and of hemin (an inducer of globin mRNA accumulation). Previously, it was shown that exposure of MELC to hexamethylene-bisacetamide (HMBA) leads to commitment, detectable within 12 hr. MELC cultured with both HMBA and dexamethasone do not express commitment. MELC transferred from culture with HMBA and dexamethasone to cloning medium without these agents express commitment to terminal erythroid differentiation, indicating that MELC retain a "memory" for some early HMBA-mediated changes leading to commitment which occur even in the presence of the inhibitory steroid. The kinetics of commitment in experiments in which exposure to HMBA is interrupted, or dexamethasone is added to the culture in HMBA, suggest that there is a rate-limiting step early in the commitment process. The memory for this step persists for more than one cell cycle. Addition of hemin to cultures with HMBA and dexamethasone initiated accumulation of globin mRNA but does not reverse the steroid-mediated inhibition of terminal cell division (that is, the cells retain their proliferative capacity). Inducer-mediated MELC commitment is associated with accumulation of the chromatin protein IP25; dexamethasone does not inhibit this accumulation. Accumulation of IP25 may be inducer-related, but it is not sufficient to cause expression of terminal erythroid differentiation.

Binding of imipramine to plasma proteins: effect of hyperlipoproteinemia

The binding of imipramine to plasma proteins was studied by equilibrium gel filtration. Imipramine was highly bound to lipoproteins as well as to other plasma proteins. The binding to the lipoproteins was higher in hyperlipoproteinemic patients than in normal subjects and correlated well with both plasma cholesterol and triglyceride levels. The overall percent binding of imipramine was also higher in hyperlipoproteinemic patients than in normal subjects. It is concluded that the varying degree of binding of imipramine to plasma proteins as a result of varying lipoprotein concentrations, as well as the special nature of the binding to lipoproteins, may be of kinetic and possibly clinical significance in hyperlipoproteinemic individuals.