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Biomedical subjects

S J Jones

Publications and source records attributed to S J Jones.

At least 127 records · Page 7Linked to original sources
PubMed1994

The effect of 3-amino-1-hydroxypropylidene-1,1-bisphosphonate (ADP) on the resorptive function of osteoclasts of known nuclear number.

Bisphosphonates (BP) are known to suppress osteoclastic resorption in vivo and in vitro, but doubt persists as to how, and the effect of BP on the resorptive capability of osteoclasts of known nuclear number is unknown. We aimed to find whether the addition of 3-amino-1-hydroxypropylidene-1,1- bisphosphonate (APD) changed the nuclear profile of an osteoclast population in vitro, and to measure the resorptive efficiency of individually characterized osteoclasts in the presence and absence of the BP. Prehatch chick bone cells were cultured for 24 hours on slices of dentine in medium with or without added APD at 10(-6) M or 10(-8) M, or in control medium on dentine presoaked with 10(-6) M APD for 48 hours. Total pit counts, and pit depths, areas and volumes for pits made by osteoclasts of known nuclear number, were found using confocal video-rate laser reflection microscopy and 3-D image analysis software. APD in the medium inhibited resorption and reduced the volume, area, and depth resorbed per nucleus per chick osteoclast. The nuclear number distribution did not shift significantly, suggesting that no preferential effect arose from the APD affecting one size of cell more than another. The large reduction found in pit numbers, depths, areas, and volumes in the APD dentine-pretreated group supports previous views that BP released during resorption act as metabolic inhibitors, altering protein synthesis by the cell. Larger cells made larger pits, but resorptive efficiency was similar for different cell sizes within the control or APD-treated groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Peptone, a low-cost growth-promoting nutrient for intensive animal cell culture.

The effect of addition of peptone to serum-free and serum supplemented media for the growth of hybridoma cells in various systems was studied. Supplementation of defined medium with either proteose peptone or meat peptone resulted in significant increases in cell number and specific monoclonal antibody production in batch culture system. Other peptones were either inactive or less effective. In continuous culture, using medium supplemented with new born calf serum, the addition of peptone resulted in 125% and 150% increases in cell and antibody concentrations respectively. Similar increase in cell number (128%) was also obtained in spin-filter perfusion culture when medium was supplemented with peptone. By comparison, the substitution of a defined 1 x MEM amino acids mixture resulted in only a 50% increase. At higher perfusion rates the cell number maintained in steady state using peptone supplement could be increased to 1.3 x 10(7) cells ml-1 while the serum concentration was reduced from 5% to 1% at a perfusion rate of 2.5 volumes per day.

Animals↗
PubMed1994

Autoantibodies to lactoferrin and histone in systemic vasculitis identified by anti-myeloperoxidase solid phase assays.

We aimed at confirming the antigen specificity recognized by anti-neutrophil cytoplasm antibodies (ANCA) in patients presenting systemic vasculitis with anti-myeloperoxidase (MPO) activity on ELISA. Thirty-five consecutive patients with reactivity in anti-MPO ELISA and systemic microscopic vasculitides were tested in slot and Western blot analyses. Eleven of 35 sera exhibited binding in Western blot studies with the MPO preparation used in the ELISA: five sera bound at the size of MPO, but five sera reacted with a 78 kD species (p78) co-purifying with MPO, and one serum blotted both MPO and p78. Sequence analysis and antigen-specific assays including Western blot studies showed that p78 is lactoferrin. All anti-lactoferrin positive sera, but no anti-MPO positive sera, also exhibited anti-nuclear binding on HEp2 cells with specificity for histone. We concluded that: (a) a subgroup of patients presenting systemic vasculitis with false anti-MPO reactivity on ELISA had anti-lactoferrin antibodies; (b) anti-lactoferrin was associated with anti-nuclear activity with specificity for histone; (c) these patients had systemic vasculitis without histological evidence of immune complex deposition.

Amino Acid Sequence↗
PubMed1994

Effects of age on the ability to remember common and rare proper names.

Difficulties in remembering proper nouns increase with age. One factor is that names are arbitrary labels. Another is that because many people share the same names, mutual discriminability between names is less than than that between other words. Discriminability between names may reduce as the number of acquaintances increases. Also, most people have both a first and a second name. These have to be learned as a pair, but they may be of unequal distinctiveness and so be unequally well remembered. An experiment was designed to evaluate the relative effects of distinctiveness of first and second names on free and cued recall. Subjects (aged 60-69 or 70-79 years, matched on Mill-Hill vocabulary score) were asked to remember one of four lists of 16 names. Each was presented four times. The names were either common, rare, or a combination of the two--a common first name with a rare surname, or vice versa. Subjects first freely recalled the names. They were next cued by either first name or surname to recall the remaining half of name pairs. Interactions between effects on recall of subjects' ages and of the relative distinctiveness of first and second names provide partial support for a model incorporating "relative distinctiveness" as a factor in failures of name recall in old age.

Age Factors↗
PubMed1994

Erectile dysfunction in multiple sclerosis. Associated neurological and neurophysiological deficits, and treatment of the condition.

Forty-eight men with multiple sclerosis and erectile dysfunction were evaluated. Emphasis was placed on the neurological features and the relationship between impotence and the bladder dysfunction in multiple sclerosis. Erectile failure was invariably associated with pyramidal signs in the lower limbs and with urinary symptoms. All of the men with impotence and marked pyramidal dysfunction in their legs were found by cystometric studies to have bladder hyperreflexia. The severity of the urinary symptoms was related to the degree of pyramidal impairment in the lower limbs. The posterior tibial and the pudendal cortical evoked potentials were abnormal in most of the men with multiple sclerosis and erectile failure. However, recording the pudendal cortical responses in patients with multiple sclerosis and impotence provided no more information than the tibial cortical evoked potentials. The neurological examination findings together with the results of the neurophysiological and cystometric tests suggest that erectile dysfunction in multiple sclerosis is due to spinal lesions situated proximal to the sacral cord. The feasability of papaverine intracorporeal injection therapy for men with multiple sclerosis and impotence was assessed. Papaverine intracorporeal injections produced satisfactory erections in the majority of the impotent men. Erectile failure in patients with multiple sclerosis was successfully managed for up to 2 years, by intracorporeal self-injection therapy.

Adult↗
PubMed1994

Temporal response of rabbits to beta-adrenergic agonist feeding: tissue weight, calpains and calpastatin activities, and nucleic acid and protein concentrations.

Forty-eight crossbred rabbits were used in three replications of a 2 x 4 factorial arrangement to investigate the short-term responses of tissue accretion, calpains and calpastatin activity, and nucleic acid and protein concentrations to beta-adrenergic agonist (BAA) feeding. Rabbits were fed a 17% CP diet with or without 7 ppm of L644,969 and slaughtered after 1, 4, 8, or 16 d of treatment. Empty body dressing percentage and biceps femoris weight (as a percentage of empty body weight [EBW]) were significantly higher in the treated rabbits than in the controls after 16 d of treatment. Heart and liver weights (as a percentage of EBW) were higher (P < .05) after 1 d and liver weight (as a percentage of EBW) was lower (P < .05) after 16 d in treated vs controls. Except for an elevation of skeletal muscle m-calpain after 16 d, BAA-supplementation did not affect the calpain-calpastatin system. Muscle RNA concentrations and RNA:DNA ratios were higher (P < .05) in treated rabbits after 1 d and remained higher thereafter. Protein:RNA ratios were lower (P < .01) in treated than in control rabbits after 4 d and remained lower throughout the trial. Muscle DNA content was lower after 4 d and higher after 16 d; RNA content was higher after 4, 8, and 16 d; and protein content was higher after 16 d in treated vs control rabbits. Liver nucleic acid and protein concentrations were not affected by BAA treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1994

Questions of quality and quantity--a morphological view of bone biology.

The quality of bone may be as important as its quantity, influencing bone strength and turnover. Using quantitative BSE (backscattered electron) imaging, we have found changes in the mineral density of bone with age, the proportion of denser bone increasing, and discontinuities occurring in the mineral phase between packets of bone. SEM of resorptive fields showed that severing of trabeculae occurs with deep, vertical excavations; their thinning is by long, narrow, resorption grooves extending from node to node. Grooved regions may become deeper, undercut and burrowing. In vitro, we showed that larger osteoclasts made larger pits. However, the volume of tissue resorbed per nucleus did not increase, and could decrease. Interactions between osteoclasts and autologous osteoblastic cells were observed by time-lapse video microscopy in vitro. Message-mediated contact behaviour, dependent upon the state of activation of both cell types, resulted in changes in the territory of the responding cell. The numbers and sizes of gap junctions between rat parietal bone cells in situ were investigated using confocal fluorescence and reflection microscopy and polyclonal antisera to connexin-43 peptides. The junctions reached approximately 1.3 microns in diameter, with 0.2 microns as the limit of detection. The extent of connectivity and communication may also affect bone quality.

Animals↗
PubMed1993

Lactoferrin co-purifies with myeloperoxidase and is recognised by anti-neutrophil cytoplasm antibodies.

Thirty-five sera with binding greater than 20% in a myeloperoxidase (MPO, Calbiochem) ELISA were tested in Western blot analyses. 5/35 blotted MPO, but 5/35 blotted lactoferrin (LF) contaminating the commercial MPO preparation. All the anti-LF positive sera, but none of the anti-MPO positive sera, also exhibited anti-nuclear binding on Hep2 cells. Three of the patients with anti-LF antibodies had vasculitis affecting areas additional to the pulmonary-renal involvement which characterised the patients with anti-MPO antibodies.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1993

The incidence and size of gap junctions between the bone cells in rat calvaria.

Polyclonal antisera to synthetic peptides matching sequences on the cytoplasmic regions of connexin-43, a gap junction protein first identified in rat heart, have been used to immunolabel gap junctions in the calvarial bone, maintained intact as in vivo, of 1- to 2-week-old rats. The specimens were examined in reflection and fluorescence modes by scanning laser confocal microscopy, and the numbers of gap junctions and their sizes estimated. The mean number of connexin-43 immunolabelled junctions per osteoblast (n = 65) was 15.3 (SD +/- 4.5). The mean length of 227 junctions, selected for the sharpness of the image of the fluorescent spot, was 0.67 micron (SD +/- 0.18; range 0.37-1.29 microns) and their mean area 0.26 micron2 (SD +/- 0.145; range 0.075-0.93 micron2); these probably fell within the upper half of the total size range. Gap junctions were detected between preosteoblasts, osteoblasts, osteocytes and chondrocytes, and between these juxtaposed cell types. In addition, connexin-43 immunolabelled junctions were found between some osteoclasts and overlying mononuclear cells at active sites of resorption.

Animals↗
PubMed1993

Visual evoked potentials after optic neuritis. Effect of time interval, age and disease dissemination.

Visual evoked potentials (VEPs) were compared among six groups of patients tested at various times after an episode of acute unilateral optic neuritis (ON). The incidence of abnormalities ranged from above 90% in patients tested during the first 6 months to about 70% when more than 2 years had elapsed. Compared with the acute stage (1-8 weeks), latency prolongation was almost 50% less in patients tested after 2-19 years. In the latter group, latencies were significantly correlated with the patients' age at the time of the attack. The findings confirm and extend the evidence of serial studies which shows that the shortening of VEP latency is a general phenomenon which proceeds for up to 2 years and possibly for longer in younger patients. When the patients with clinically isolated ON were compared with those who had a history of additional neurological episodes suggestive of multiple sclerosis (MS), up to 4 weeks after ON latencies were more prolonged in the MS group but between 4 and 8 weeks amplitudes were larger and between 8 weeks and 2 years latencies were significantly shorter. No significant differences were found in patients tested after more than 2 years. It is suggested that the electrophysiological deficit may initially be more severe in patients with disseminated disease, but that recovery may occur faster.

Adolescent↗
PubMed1993

Scanning electron microscopy of human lumbar vertebral trabecular bone surfaces.

Trabecular bone from fourth lumbar vertebral bodies of 30 autopsy subjects (18 male and 12 females, 30-91 years of age) was investigated using surface mode scanning electron microscopy. In the younger individuals, proper coupling of formation and resorption appeared to have maintained both the bone mass and the shape and structural integrity of the trabecular elements. In elderly individuals, including osteoporotics, irregularities and uncoupling of these activities brought about a loss of bone and a disruption of trabecular structure. Distinct resorption patterns (lateral and vertical) are responsible for trabecular thinning and removal of structural elements. Irregularities in the formative process in old age may account for the compensatory thickening and changes in shape and texture of trabecular elements. The mechanisms involved in the occurrence of microfractures and the fate of disconnected elements were also identified. An increased proportion of arrested mineralizing fronts is found in older individuals and in frank osteoporotics. Resorption may occur through osteoid and arrested mineralizing fronts, as well as through resting, fully mineralized surfaces.

Adult↗
PubMed1993

Effects over time of feeding a beta-adrenergic agonist to wether lambs on animal performance, muscle growth, endogenous muscle proteinase activities, and meat tenderness.

Forty wether lambs were used in a 2 x 4 factorial arrangement to determine the response of animal performance, muscle growth, proteinase activity, and meat tenderness to beta-adrenergic agonist (BAA) supplementation. Lambs were fed a finishing diet with or without 4 ppm of L644,969 and slaughtered after 0, 2, 4, and 6 wk of treatment. The ADG was higher (P < .05) in the treated than in the control lambs after 2 wk and returned to control levels thereafter. Semitendinosus weight and calpastatin activity were higher and mu-calpain activity was lower in the treated than in the control lambs after 2, 4, and 6 wk. Cathepsin B activity was higher (P < .01) and cystatin-like activity was lower (P < .05) after 2 wk in treated than in control lambs but returned to control levels thereafter. Longissimus protein:DNA was higher after 4 (P < .05) and 6 (P < .01) wk in the treated lambs than in the controls. The concentration of RNA and RNA:DNA ratio were higher (P < .01) in the longissimus and semitendinosus muscles in the treated lambs after 2 wk and remained higher throughout the study. Semitendinosus protein and RNA content were higher after 2, 4, and 6 wk and DNA content was higher after 2 and 6 wk in the treated than in the control lambs. Longissimus shear-force values were higher (P < .001) in the treated than in the control lambs at all slaughter end points. These data indicate a rapid alteration of muscle growth, activity of the calpain-calpastatin system, and meat tenderness during BAA treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1993

Testosterone, dihydrotestosterone, trenbolone acetate, and zeranol alter the synthesis of cortisol in bovine adrenocortical cells.

The objective of this study was to examine the effect of anabolic steroids (testosterone, T; dihydrotestosterone, D; trenbolone acetate, B; and zeranol, Z) on cortisol synthesis by cultured bovine adrenocortical cells. Adrenal glands were obtained from slaughter-aged steers (n = 4). Cortical cells were isolated and their steroidogenic capacity was examined. They were plated in multiwell culture plates. At confluence, cells were treated with T, D, B, or Z at 0, 10, 50, 125, or 500 ng/mL (eight wells per treatment). Twenty-four hours after treatment, one-half of each treatment concentration was stimulated with 10(-9) M ACTH. After 8 h of incubation, cortisol concentration in the media was measured using RIA. Cortical cells were removed from the plates using 1 mM EDTA and analyzed for DNA content. Data were subjected to rank transformation and analyzed by randomized complete block design. Adrenocorticotropic hormone stimulated (P < .01) the release of cortisol by more than threefold. Cortisol synthesis was lower (P < .05) in the presence of T, D, and B. Testosterone caused a greater (P < .05) suppression in cortisol production at 50 and 125 ng/mL than did D. The suppression of cortisol synthesis did not differ between B and T or between B and D. Cortisol synthesis was lowered (P < .05) by the presence of T, D, and B in both ACTH-stimulated and nonstimulated cells but was only suppressed in ACTH-stimulated cells of Z-treated cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex↗
PubMed1993

A simple way to make traction pins safer.

Prevention of inadvertent injuries to patients and hospital staff becomes more important than ever in today's hospital environment. The sharp ends of traction pins, a previous hazard, can be made safe using materials easily found throughout the hospital. Our method uses items that are easily replaced and easy to apply.

Bone Nails↗
PubMed1992

The relationship between the number of nuclei of an osteoclast and its resorptive capability in vitro.

This study examined the relationship between the number of nuclei in an osteoclast and its resorptive efficiency, as demonstrated by the size of the pit it can make in a mineralized tissue in 24 h in vitro. Osteoclasts released mechanically from prehatch chick long bones were cultured on dentine slices or on plastic dishes for periods of 6 or 24 h. The frequency distribution of the multinucleate tartrate-resistant acid phosphatase (TRAP)-positive cells with different numbers of nuclei was determined: the mean number of nuclei per cell was 6.92, with a mode of 4.47% had 5 or fewer nuclei and only 11% more than 10 nuclei. The pits associated with 292 osteoclasts with known numbers of nuclei were measured using a confocal laser light microscope (Lasertec) and dedicated image analysis system, and depths, plan areas and volumes determined. There was a positive correlation between the number of nuclei per osteoclast and the volume of the pit made, but a trend for the volume resorbed per nucleus to decrease with increase in the number of nuclei per osteoclast.

Animals↗