Biomedical subjects
R Moss
Publications and source records attributed to R Moss.
Macrophage colony-stimulating factor stimulates survival and chemotactic behavior in isolated osteoclasts.
Macrophage colony-stimulating factor (M-CSF) is known to play an important role in osteoclast formation. However, its actions on mature cells have not been fully characterized. We now report that M-CSF dramatically stimulates osteoclastic motility and spreading; osteoclasts responded to a gradient of M-CSF with orientation, and random cell polarization occurred after isotropic exposure. M-CSF also supported the survival of osteoclasts by preventing apoptosis. Paradoxically, M-CSF inhibits bone resorption by isolated osteoclasts. We found that this was effected predominantly by reduction in the number of excavations. Thus, M-CSF showed a propensity to suppress resorption through a reduction in the proportion of cells that were resorbing bone. Our data suggest that apart from the established role of M-CSF in the provision of precursors for osteoclastic induction, a major role for M-CSF in bone resorption is to enhance osteoclastic survival, migration, and chemotaxis. It seems appropriate that during these processes resorptive functions should be suppressed. We suggest that M-CSF continues to modulate osteoclastic activity once osteoclasts are on resorptive sites, through regulation of the balance between resorption and migration, such that not only the quantity, but the spatial pattern of resorption can be controlled by adjacent M-CSF-secreting cells of osteoblastic lineage.
Muscle GLUT 4 protein levels and impaired triglyceride metabolism in streptozotocin diabetic rats. Effect of a high sucrose diet and fish oil supplementation.
Our data indicate that (a) the existence of a defect in the clearance of circulating TG and persistence of muscle TG deposition in the high sucrose-fed neonatal streptozotocin diabetic rat, which (b) can only be partially corrected by raised dietary n-3 PUFA intake. (c) Skeletal muscle of STZ type II-like diabetic rats contains about 40% less glucose transporters, and (d) this situation cannot be changed by any of the dietary treatments employed. (e) These findings indicate that muscle TG accumulation may have no direct relation to glucose transport in muscle.
The effect of insulin on proteins associated with free, cytoskeletal-bound and membrane-bound polysome populations.
It is known that insulin treatment increases the rate of protein synthesis in many cells and tissues and that it causes changes in the distribution of ribosomes between free (FP), cytoskeletal-bound (CBP) and membrane-bound polysome (MBP) populations. This paper concerns an analysis of the pattern of proteins in high-salt extracts of FP, CBP and MBP isolated from Krebs II ascites and MPC-11 cells. A combined detergent/salt extraction procedure was used to isolate the three fractions of polysomes from control cells and from cells following short-term stimulation with insulin. There were differences in the protein patterns in the individual fractions and changes occurred after insulin stimulation.
Caecal threadworms Trichostrongylus tenuis in red grouse Lagopus lagopus scoticus: effects of weather and host density upon estimated worm burdens.
Trichostrongylus tenuis eggs were counted in faeces from individually marked wild red grouse for 8 years. Egg counts varied seasonally and annually. In some years, a sudden increase in mid-April was consistent with delayed maturation of larvae which had overwintered in the birds in a hypobiotic state. A more gradual increase in summer was probably due to uninterrupted maturation of larvae ingested then. Despite 30-fold year-to-year variation in mean egg counts, relative differences in egg counts among known individuals within years tended to persist across years. Rainfall in previous summers explained much of the year-to-year variation in egg counts, probably because parasite recruitment was greatest during wet summers. Grouse density was only weakly related to worm egg counts. The data were not consistent with the hypothesis that the cyclic-type population fluctuation in red grouse numbers observed at the time of this study was caused by the parasites.
Dopexamine hydrochloride maintains portal blood flow and attenuates hepatic ultrastructural changes in a porcine peritonitis model of multiple system organ failure.
Fifteen anesthetised pigs (25-30 kg) were divided into three equal groups, sham, dopexamine (D) (10 micrograms/kg/min), and placebo (P). Sepsis was induced by fecal peritonitis in the D and P groups and colloid was infused to try to maintain mean arterial blood pressure (MABP) at a constant value and the hemodynamics measured at baseline and hourly for 8 hr. There was an initial increase in MABP and systemic vascular resistance (SVR) in the P group but not the dopexamine (D) group. Cardiac output (CO) in the P group showed a small decline but increased in the D group. The portal blood flow (PVF) in the P group fell with MABP but increased in the D group as MABP fell. The sham group showed normal ultrastructure and cellular integrity. Occlusion of the hepatic sinusoids was similar in the D and P groups. There was a greater area of Kupffer cells and endothelial cells in the P group, suggesting a greater inflammatory reaction than was found in the D group. Ultrastructure and mitochondrial integrity was better maintained in the D group. Dopexamine hydrochloride infusion maintained CO, increased PVF, and attenuated hepatic ultrastructural changes compared to placebo in a porcine fecal peritonitis model of multisystem organ failure.
An idiotypic replica of carcinoembryonic antigen inducing cellular and humoral responses directed against human colorectal tumours.
A monoclonal anti-idiotypic antibody (anti-Id MAb) 708 (IgG2b), which inhibited the binding of NCRC23 (IgG1) MAb to CEA and prevented radiolabelled CEA from binding to MAb NCRC23, was produced. No recognition of 3 other anti-CEA antibodies, 3 other IgG1 or 2 IgM MAbs was observed with this anti-idiotypic antibody. When an immunoblotting technique was used, 708 anti-Id MAb failed to bind to isolated heavy or light chains of MAb NCRC23, whereas binding was observed with intact antibody. Mouse, rat and human lymphocytes (in vitro) were immunized with 708 anti-Id MAb and the resultant Ab3 antibodies all inhibited binding of labelled 708 anti-Id MAb to MAb NCRC23 and also reacted with CEA, showing that 708 anti-Id MAb induced anti-CEA antibody responses. Similarly, mice immunized with 708 anti-Id MAb could be restimulated in vitro with either CEA or tumour cells expressing CEA which induced specific T-cell proliferative responses. Human tumour-infiltrating lymphocytes isolated from colorectal tumours or peripheral blood T cells from cancer patients were stimulated in vitro with 708 anti-Id MAb or an irrelevant IgG2b antibody. Six days later both sets of lymphocytes were restimulated with CEA, and lymphocytes primed to 708 anti-Id MAb proliferated in response to CEA. These results suggest that 708 anti-Id MAb can act as an idiotypic replica of CEA and stimulate cellular and humoral anti-CEA immune responses. It is therefore of great interest as an idiotypic vaccine against colorectal cancer.
Cardiac rupture from blunt trauma.
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Difference in patterns of proteins isolated from polysomes in free, cytoskeleton-bound and membrane-bound fractions in MPC-II cells incubated with insulin.
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Diet selection--an ecological perspective.
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Goal directed therapy with dobutamine in a porcine model of septic shock: effects on systemic and renal oxygen transport.
Systemic and renal haemodynamic and functional indices were measured in 15 anaesthetised pigs during systemic sepsis induced by faecal peritonitis. Five animals were assigned to maintenance of cardiac output (CO) at baseline, pre-infection values throughout the study (controls n = 5). In the remaining 10 animals, CO was increased by 25% prior to induction of sepsis and maintained at this level for the duration of the study using volume expansion with intravenous colloid and an infusion of either 20 micrograms/kg/min dobutamine (n = 5) or placebo (n = 5). Hourly measurements were made of CO, left renal blood flow, arterial and renal venous oxygen saturation, urine output, creatinine clearance and arterial partial pressure of oxygen until the animal died or until termination 8 h. Systemic indices of oxygen transport did not reflect the behaviour of the renal vascular bed during the management of sepsis. In the dobutamine group systemic oxygen uptake (VO2) increased from 173 +/- 30 to 277 +/- 73 ml/min (P less than 0.05), however this resulted in a decrease in renal DO2 (20 +/- 9 to 10 +/- 2 ml/min P less than 0.05) and there was no equivalent rise in renal VO2 (3.3 +/- 1.6 to 3.2 +/- 1.5 ml/min). There was however no significant difference in the effect on renal function of the three management protocols. Agents used to increase cardiac output during systemic sepsis may result in significantly different effects on the renal vascular bed which are not revealed by the measurement of systemic indices alone.
Adenomatous polyp of the fallopian tube. A case report.
Benign epithelial lesions of the fallopian tube are rare. An adenomatous polyp of the fallopian tube was discovered incidentally at laparotomy.
New developments in neutron capture therapy.
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Comparative effects of three cereal brans on plasma lipids, blood pressure, and glucose metabolism in mildly hypercholesterolemic men.
Dietary fiber lowers atherogenic serum lipids and blood pressure and improves glucose metabolism. We compared in 24 mildly hypercholesterolemic men the effects of adding 11.8 g dietary fiber/d from each of three cereal brans (wheat, rice, and oat) to a low-fiber diet for 4 wk each. A double-blind, crossover design incorporated brans into bread and muffins. Plasma total- and low-density-lipoprotein-cholesterol concentrations were significantly lowered only by oat bran. Compared with wheat bran, the ratios of plasma high-density-lipoprotein cholesterol to total cholesterol and of apolipoprotein A-I to B were significantly increased with oat bran (both by 4.7%, P less than 0.05), and rice bran (2.3%, P less than 0.05, and 3.9%, P less than 0.05, respectively). Blood pressure, blood glucose, and serum insulin responses to a common test meal were unaltered. Oat and rice bran exert a small but potentially useful effect on plasma lipoprotein risk factors for cardiovascular disease.
Pretreatment with pentoxifylline improves the hemodynamic and histologic changes and decreases neutrophil adhesiveness in a pig fecal peritonitis model.
We investigated pentoxifylline (PTF) as a pretreatment of septic syndrome in pigs with fecal peritonitis. In the untreated group there was a progressive decrease in mean arterial pressure (MAP), cardiac output, mean pulmonary artery wedge pressure (WP), and a progressive rise in mean pulmonary artery pressure (MPAP), pulmonary vascular resistance (PVR), systemic vascular resistance (SVR), heart rate (HR), and core temperature (T). In those pigs given PTF there was a significantly smaller increase in SVR throughout and in PVR after 270 min. No significant differences were seen in MAP, MPAP, WP, HR, and T. Neutrophil adhesiveness did not change in the untreated group. However, it decreased markedly with PTF, both before and after peritonitis induction. Electron microscopy of the lungs, liver, and spleen in the test group showed severe damage, with endothelial disruption, capillary or sinusoidal occlusion, leukostasis, and neutrophil degranulation. Pretreatment with PTF attenuated these changes.
Relevance of serum phospholipase A2 assays to the assessment of septic shock.
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Effects of the caecal nematode Trichostrongylus tenuis on egg-laying by captive red grouse.
Captive hen red grouse infected with Trichostrongylus tenuis larvae started to lay later in spring and laid fewer eggs at a slower rate than uninfected hens. March-infected hen grouse showed greater effects than December-infected ones, probably because developing larvae were more pathogenic than adult worms. The mechanism by which parasites interfered with egg production involved reduction in food intake. Infected hens also gained less weight than controls before laying.
Gut size and the digestion of fibrous diets by tetraonid birds.
A series of diets containing different proportions of heather was fed to red grouse. Heather is the bird's main natural food and contains much fiber; the rest of each diet was a relatively low-fiber, grain-based formulation. With increasing heather and associated fiber contents, food intake increased and overall digestibility of heather was only 9.4%, but, when heather was eaten as the sole food by wild red grouse, its digestibility was 46%. Adaptations to diets containing more heather included increases in the size of the digestive system. Gizzard weight increased linearly with food intake. Lengths of intestines and particularly ceca also increased with intake, but not linearly. Up to an intake of about 50 g dry matter/day no significant change occurred. Above 50 g/day, gut size increased rapidly. Bulk may have started to limit intake at about 50 g/day. One can think of galliform digestion functioning in two modes: 1) a low-fiber mode, in which bulk does not limit intake and fiber digestion is unimportant; and 2) a high-fiber mode, in which bulk limits intake and fiber digestion may well be important. Most studies on avian digestion have been of captive galliforms, most of which probably function in low-fiber mode all the time. Wild galliforms seem to function in high-fiber mode for much of the time, but this has been studied little.