Cell interactions influencing murine marrow megakaryocytes: nature of the potentiator cell in bone marrow

Auxiliary bone marrow cells are required for optimal murine megakaryocyte colony formation in addition to progenitor cells and a colony stimulating activity (CSA) present in WEHI-3 cell conditioned medium. These auxiliary cells are adherent, with a sedimentation rate of 5.8 mm hr-1 and buoyant density of 1.065-1.078 gcm-3. The activity from bone marrow cells is loss at irradiation doses above 900 rad. Bone marrow cells with these characteristics, and supernatants from lung, bone shafts, and peritoneal exudate cells were all active in enhancing megakaryocyte colony incidences in mouse bone marrow cultures above those stimulated by an obligatory activity in WEHI-3 cell conditioned medium. Certain macrophage cell lines (J774, P388D1) could elaborate the activity. This study confirms that a potentiation activity enhances CSA stimulation of megakaryocyte colony formation. The potentiator is elaborated by bone marrow cells in limiting amounts requiring either high cell concentrations or an exogenous source of the activity for optimal colony growth.

Antifertility and toxicological studies with aromatic esters of alpha-chlorohydrin in male rats

Due to the drawbacks in the potential use of alpha-chlorohydrin itself as a male oral contraceptive, two novel crystalline derivatives, alpha-chlorohydrin-bis-m-nitrobenzoate and alpha-chlorohyrdin-mono-p-acetamidobenzoate, were synthesized and tested for antifertility activity in male rats. In addition, the nephrotoxic effects of alpha-chlorohydrin itself and of the two aromatic esters were investigated by the use of diuretic experiments, plasma biochemical analyses and kidney histology. Both esters were found to be of comparable molar potency to alpha-chlorohydrin in inducing temporary infertility following daily oral administration. The nephrotoxic effects following high oral doses of alpha-chlorohydrin were largely eliminated by the use of either ester. These derivatives have several advantages over alpha-chlorohydrin, being crystalline compounds of definable purity. Although potency was retained, acute oral toxicity was greatly reduced, due to a combination of factors - the esters were poorly absorbed in high dosage whilst relatively slow breakdown permitted effective levels to be attained on epididymal spermatozoa.

Limitation of macrophage production in long-term marrow cultures containing prostaglandin E

Addition of prostaglandin E2 (PGE2) significantly altered the cellular composition of murine long-term bone marrow cultures. After 4--5 weeks of culture, increased cellularity in the suspension phase was observed in all cultures containing prostaglandin. These suspension cells contained markedly higher proportions of differentiated neutrophils than did cells cultured in the absence of PGE2. Granulocyte-macrophage progenitor cell levels in the suspension layer were increased 3--20 fold after five weeks in prostaglandin-containing cultures compared with control cultures. Fewer cells comprised the adherent layer in cultures containing prostaglandin. The number of macrophages in this layer was reduced 3--8 fold in these cultures compared with control cultures, while the number of granulocytes was increased 2--3 fold. The progenitor cells biased toward macrophage development were selectively inhibited in the cultures with PGE2. There was no significant effect of PGE2 on pluripotent stem cell levels or on the longevity of the cultures. It is concluded that excessive monopoiesis in bone marrow may be limited by PGE2 without influencing either stem cell maintenance or the development of other marrow-derived cell types.

Isolation of pluripotent hemopoietic stem cells and clonable precursor cells of erythrocytes, granulocytes, macrophages and megakaryocytes from mouse bone marrow

Murine pluripotent hematopoietic stem cells and precursor cells with restricted commitment to erythrocytes, granulocytes and macrophages as well as megakaryocytes have been purified 30- to 50-fold from mouse bone marrow cells. Purification was achieved by a three-step procedure. Bone marrow cell populations free of erythroid cells and lymphocytes were obtained by culturing the cells for several weeks. Macrophages and adherent polymorphic neutrophils (PMN) were removed by adherence to plastic. The remainder of the PMN along with more primitive granulocytes (but not promyelocytes and some monocytoid cells) were removed either by neutral density centrifugation or by differential centrifugation after rosette formation with sheep erythrocytes coated with immunoglobulin (EA rosettes). The remaining population of marrow-derived cells contained 40-66% blast cells, 20-35% promyelocytes and 5-10% other cells (usually PMNs and monocytes). Using cloning techniques to detect immature hemopoietic cells, this population contained 15-35% granulocyte-macrophage progenitor cells, approximately 0.2% erythroid burst-forming cells, approximately 0.1% megakaryocyte progenitor cells and 1-3% pluripotent stem cells (based on seeding efficiency 0.06).

Pleomorphism in Cellulomonas acidula

Pleomorphism of Cellulomonas acidula in liquid and on solid media is described. Growth in liquid medium is characterized initially by the formation of club-shaped rods and later by cocci. On solid media the organism formed irregular branched cells and large swollen cells.

Effect of racemic and S(+) alpha-chlorohydrin-1-phosphate on glyceraldehyde-3-phosphate dehydrogenase in relation to its contraceptive action

The phosphate esters of racemic (+/-) alpha-chlorohydrin and its S(+)-optical isomer have been prepared as cyclohexylamine salts. In vitro both inhibited glyceraldehyde-3-phosphate dehydrogenase by a competitive mechanism, whereas (+/-) alpha-chlorohydrin did not. The S(+)-isomer was approximately four times as potent as the racemate. These results correlate with data concerning the relative contraceptive activity in rats of racemic and S(+) alpha-chlorohydrin. They support the view that the antifertility mechanism involves in vivo formation of S(+) alpha-chlorohydrin-1-phosphate, with resulting inhibition of glycolysis in sperm.

Ontogeny of behavioral responsiveness to sound in the chick embryo as indicated by electrical recordings of motility

The primary purpose of these experiments was to gather normative behavioral data regarding the ontogeny of responsiveness to sound in the chicken embryo. As a prerequisite, a sensitive ane accurate method for recording embryonic motility was developed (Experiment 1). By means of platinum electrodes inserted just beneath the shell membrane, potentials resulting from heartbeat and movement were recorded on a polygraph. The technique was found to be effective when applied to chick embryos 6 days and older. Correlations between visual observations of activity and the records produced by the electronic technique substantiated its accuracy. Behavioral responses of chick embryos (Stages 39-43) to acoustic stimulation (Experiment 2) were then recorded. High-intensity (115-dB SPL) tones of 400, 700, and 1400 Hz were used as stimuli. The earliest consistent responses were recorded from Stage 40 (ca. Days 14-15) subjects; the 700 and 1400 Hz tones produced statistically reliable inhibition of movement during the stimulus period compared with the post-stimulus period. Reliable increases in movement during the stimulus period were first recorded at Stage 42 (ca. Days 16-17) in response to 700 and 1400 Hz and at Stage 43 (ca. Days 17-18) in response to 400 Hz.

Regulation of proliferation of murine megakaryocyte progenitor cells by cell cycle

The extent to which mouse megakaryocyte progenitor cells (colony-forming unit-megakaryocyte, CFU-M) can proliferate in semisolid cultures prior to endomitosis, and conditions that may regulate that differentiation step, were investigated. The proliferative capacity of CFU-M was determined by estimating the number of megakaryocytes per colony. A bimodal distribution was observed (modal values, 10-15 and 25-30 cells/colony), indicating that separate megakaryocyte progenitor cells may be biased in their capacity for proliferation versus endomitosis. Differences were observed in the cell cycle characteristics of CFU-M as determined in vivo and in vitro that suggest that maturation of CFU-M into megakaryocytes may be regulated within the marrow by control of the cell cycle of the megakaryocyte precursor cell.

Regulation of megakaryopoiesis in long-term murine bone marrow cultures

Megakaryocytes and their precursor cells were sustained in mouse bone marrow suspension cultures for over 4-6 wk. Megakaryocyte precursor cells were detected by their capacity to form colonies of megakaryocytes in semisolid agar cultures. Colony formation was dependent on the presence of medium conditioned by a myelomonocytic leukemic cell line (WEHI-3CM). Megakaryocytes from the liquid and semisolid cultures were identified by cytoplasmic acetylcholine esterase and by ultrastructural analysis. The suspension medium from the bone marrow liquid cultures which sustained megakaryopoiesis was not directly acitive in stimulating megakaryocyte colony formation in the semisolid agar cultures, but potentiated the number of colonies detected when WEHI-3CM was present. Bone marrow-conditioned medium increased the sensitivity of megakaryocyte progenitor cells to the stimulus in WEHI-3CM. Addition of the activities present in the two sources produced a quantitative assay for the detection of mouse megakaryocyte progenitor cells. These studies showed: (1) that no inductive regulator of in vitro clones of megakaryocytes was present in the supernatants from the long-term marrow cultures and, (2) that at least two factors were necessary for the induction of megakaryocyte progenitors to proliferate and differentiate in semisolid cultures in vitro.

Proliferation and differentiation of normal granulopoietic cells in continuous bone marrow cultures

Modified conditions are reported for successful continuous bone marrow cultures with stem cell self-renewal and granulocyte-macrophage differentiation. Cells cultured over several weeks were found to be identical to freshly isolated bone marrow cells. Polymorphic neutrophils derived from cultures and primary bone marrow neutrophils both showed C3 AND IgG receptors and both actively phagocytosed foreign particles. Cultured and normal CFU-c were identical, both in their dose responsiveness to CFS and in their sedimentation rate characteristics.

Analysis of populations of macrophage-granulocyte progenitor cells stimulated by activities in mouse lung-conditioned medium

Granulocyte and macrophage progenitor cells which clone in semi-solid agar cultures were characerized by separating murine bone marrow cells by equilibrium density centrifugation. These in vitro colony forming cells (CFU-c), when induced by stimuli in mouse lung-conditioned medium, were found to be heterogeneous in their density properties. Differences were found in the dose responsiveness of two major subpopulations of these progenitor cells. One population (modal density 1.074 gcm-3) responded in an identical manner to stimuli present in mouse lung-conditioned medium and pregnant mouse uterus extract. A second population (modal density 1.070 gcm-3) was found to be markedly different in its dose responsiveness to mouse lung-conditioned medium, from the other subset (1.074 gcm-3). The cloning of the low density progenitor cells and the observed dose responsiveness was found to correlate with an activity present in a stimulus in mouse lung-conditioned medium but was not identical to the stimulus in pregnant mouse uterus extract. No subpopulation, however, gave exclusively granulocyte or macrophage colonies.

The sleepless child

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Streptococcal control in grade schools

Streptococcal infection has been reduced by some school-centered programs. This controlled study evaluates the relative effectiveness and cost of four different school programs: (1) Each day, throat specimens from children with sore throats were cultured. (2) Each week, all children were inspected and specimens from those with signs of pharyngitis were cultured. (3) Specimens from all students were cultured once each month. (4) Same as protocol 3, but students with positive cultures were excluded from school until they began receiving therapy. Schools using protocols 1 and 4 had substantial reduction in streptococcal prevalence. The monthly "all-student program" was most economical in terms of volunteer time, classroom interruption time, and money. The school culturing program may have contributed to a significant decline of rheumatic fever in the county during the study.

Comparative effects of niridazole on spermatogenesis and reproductive capacity in the mouse, rat and Japanese quail

Niridazole is an effective schistosomicidal compound which, at lower dose levels, affects schistosome gonads. Its antifertility and possible mutagenic effects after various courses of oral treatment were compared in mice, rats and Japanese quail (Coturnix coturnix japonica). In all three species the meiotic stage of spermatogenesis was particularly affected. In mice the highest dose rate (five daily doses of 100 mg/kg) produced sterility during the 4th week. Rats were more susceptible, the compound producing prolonged and, in some animals, permanent sterility against which HCG treatment offered no protection. In quail only a brief phase of sterility occurred. Niridazole appears to be non-mutagenic since dominant lethal mutations were not produced in dose-response studies. Minimal changes in testis histology occurred in the mouse, but in rats severe damage persisted even in animals which had recovered their fertility.

Antibodies to spermatozoa. VI. Comparative studies of sperm-agglutinating activity in groups of infertile and fertile women

In order to evaluate the significance of sperm antibodies in relation to infertility, studies have been made on both infertile and fertile populations. The infertile population consisted of about 150 couples with long-standing infertility, predominantly of the unexplained type. The fertile population consisted of 78 antepartum women and 35 postpartum women. In all these individuals, sperm antibody was sought by two methods of serum testing, namely, the Kibrick (K-B-M) and the F-D methods of sperm agglutination. In the infertile group, the Kibrich test was positive for 23.1 per cent of the women and 9.6 per cent of the men, whereas the F-D test was positive in 16.4 per cent of the women and 5.0 per cent of the men. In contrast to these values, it was found in the fertile group that the Kibrick test was positive in 2.7 per cent of these women and the F-D test was also positive in 2.7 per cent of them. A number of technical details and precautions have also been emphasized. These principles are intended to minimize the occurence of nonspecific and false-positive results.

Parthenogenic development after chemical treatment of Xenopus laevis spermatozoa

Eggs of Xenopus laevis were fertilized in vitro by spermatozoa pre-treated with various concentrations of aziridinyl urea (ethyleneurea) for between 30 and 120 minutes. At 2 and 4 mg/ml for 30 minutes there was a high incidence of abnormal embryos, few of which developed into tadpoles; after 6 and 8 mg/ml no tadpoles were produced. However, the highest concentration 10 mg/ml, yielded 66% of tadpoles, only 7% of which were obviously abnormal. With increasing time the same pattern of events was obtained except for a displacement towards the lower concentration ranges. Tadpoles developing from these latter experiments were found to be haploid. The results resemble those obtained by exposure of Rana pipiens spermatozoa to X-rays and ultraviolet light, with the production of gynogenetic embryos, usually referred to as the Hertwig effect.

Congenital absence of a pedicle in a cervical vertebra

The importance of agenesis of a pedicle lies in its resemblance to a destructive lesion of the pedicle or to an expanding lesion in an intervertebral foramen. The correct diagnosis can be made roentgenologically by demonstrating a widened intervertebral foramen at the level of an absent pedicle with posterior displacement of the maldeveloped lateral mass. Two cases of agenesis of a pedicle in a cervical vertebra are presented.

Pharyngeal culture program in Colorado

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