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.

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)

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.

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.

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)

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.

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)

Video-rate confocal reflection microscopy of neoplastic cells: rate of intracellular movement and peripheral motility characteristic of neoplastic cell line (RSK4) with high degree of growth independence in vitro

Video-rate laser confocal interference reflection microscopy was used to demonstrate rapid motion of intracellular organelles and features at the cell periphery in a fully transformed neoplastic cell line, RSK4, and in four other neoplastic cell populations. In the RSK4 cells, vibrational and trafficking movements of intracellular particles at a rate greater than 25 Hz and ranging down to 5 Hz were recorded. Rapidly moving processes changed to ruffles, then microspikes, and previously undetectable ephemeral intercellular contacts were seen. Dynamic cyclical changes were revealed in the sizes of the podosomal close contacts of the transformed cells. The visibility of such features and the temporal and spatial resolution are improved over earlier methods. The fact that fast cellular and intracellular movements can be detected with this microscopic technique offers new possibilities in attempting to recognise differences between unimpaired living cells, and it may prove useful in the identification of malignant cells.

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.

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.

Behaviour of osteoclasts in vitro: contact behaviour of osteoclasts with osteoblast-like cells and networking of osteoclasts for 3D orientation

The cell-cell contact-induced behaviour of osteoclasts and osteoblasts in vitro was investigated by time-lapse videomicroscopy. Contact interactions of osteoclasts with autologous cells, derived mostly from chick but also from rat bones, included contact inhibition, failure of contact inhibition, contact guidance along stabilised edges of other cells, and underlapping of other cells. Message-mediated contact behaviour (MMCB) between osteoclasts and autologous osteoblastic cells resulted, after a time delay, in zeiosis of the osteoblast-like cell which could continue, or even begin, after the osteoclast broke contact, leading to retraction of the cell and occupation of its position by the osteoclast. MMCB may play a part in the breaching of the osteoblastic sheet by osteoclasts and, in general, in the malignant spread of neoplastic cells. Two or more osteoclasts were often joined by connecting and coordinating tubules (CCTs) of varied, and varying, lengths and widths. Osteoclasts could travel along the CCTs in both directions, or send nuclei through them. The CCTs became temporarily attached to the surface of other cells, or to the substrate, then acting as a temporary anchorage for orientation and for the return of the cell to the same spot. The dynamics of osteoclastic behaviour suggest that such a networking of osteoclasts is valuable for the 3D coordination of their role in bone turnover.

Rapid neural growth: calcitonin gene-related peptide and substance P-containing nerves attain exceptional growth rates in regenerating deer antler

Deer antler is a unique mineralized tissue which can produce very high growth rates of > 1 cm/day in large species. On completion of antler growth, the dermal tissues which cover the antler are shed and the underlying calcified tissue dies. After several months the old antler is discarded and growth of a new one begins. It is known that deer antlers are sensitive to touch and are innervated. The major aims of this study were to identify and localize by immunohistochemical techniques the type of innervation present, and to find out whether nerve fibres could exhibit growth rates comparable to those of antler. We have taken tissue sections from the tip and shaft of growing Red deer (Cervus elaphus) antlers at three stages of development; shortly after the initiation of regrowth, the rapid growth phase, and near the end of growth. Incubation of tissue sections with antisera to protein gene product 9.5 (a neural cytoplasmic protein), neurofilament triplet proteins (a neural cytoskeletal protein), substance P and calcitonin gene-related peptide (both of which are present in and synthesized by sensory neurons) showed the presence of immunoreactive nerve fibres in dermal, deep connective and perichondrial/periosteal tissues at all stages of antler growth. The sparse distribution of vasoactive intestinal polypeptide-like immunoreactivity was found in dermal tissue only at the earliest stage of antler development. Nerve fibres immunoreactive to neuropeptide Y, C-flanking peptide of neuropeptide Y and tyrosine hydroxylase, all present in postganglionic sympathetic nerves, were not observed at any stage of antler growth. Nerves expressing immunoreactivity for any of the neural markers or peptides employed could not be found in cartilage, osteoid or bone. These results show that antlers are innervated mainly by sensory nerves and that nerves can attain the exceptionally high growth rates found in regenerating antler.

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.

Response time of broiler chickens to cimaterol: meat tenderness, muscle composition fiber size, and carcass characteristics

The response time to cimaterol (CIM), a beta-adrenergic agonist, by broiler chickens for carcass characteristics, muscle composition, muscle fiber size, catheptic enzyme activity, and tenderness was determined. Two trials were conducted in which chickens were fed a control diet (CON) containing 0 ppm of CIM or a diet containing 1 ppm of CIM. Trial 1 consisted of 55, 31-d-old broiler chickens individually fed for up to 48 h. At 0, 6, 12, 18, 24, and 48 h, five CON and five CIM-fed chickens were killed. Trial 2 consisted of 160, 33-d-old broiler chickens group-fed for up to 14 d. At 2, 4, 6, 8, 10, 12, and 14 d, 10 CON and 10 CIM-fed chickens were killed. The breast muscle (BM) and leg muscle (LM) weight, cathepsin B and L activities, DNA, RNA, and protein concentration, and BM shear force value (SFV) were measured in both trials. Thigh muscle (TM) SFV were measured in Trial 2 only. Fiber size of BM was measured (five birds per treatment) at d 2, 6, 10, and 14. In Trial 1, BM weight and SFV were lower in CIM-fed birds at 6 h (P less than .05). In Trial 2 BM SFV were higher at d 8 (P = .06) and d 10 (P less than .05) in CIM-fed chickens. The SFV of CIM-fed chickens were higher at d 4, 8, 10, 12, and 14 (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

AEPs at the onset and offset of repetitive sound modulation, due to mismatch with the contents of an auditory sensory store

Long latency auditory evoked potentials (AEPs), chiefly consisting of a negative peak at about 150 msec and a positivity at 250 msec, were recorded at the beginning and end of periods during which the interaural time difference of binaural noise was switched between 0.0 and 0.8 msec at a fast rate (ISI = 50 or 25 msec) or the frequency of continuous binaural clicks was switched between 167 and 200 Hz every 80, 50 or 25 msec. In the latter case the offset responses occurred later than onset by a mean of 89, 47 and 27 msec respectively, suggesting they were probably generated at the moment the next switch was expected but failed to occur. The offset responses must be non-specific with respect to the interaural delay or the frequency of clicks, since neurones which respond to particular delays or frequencies and are made refractory by a rapid rate of stimulation should not suddenly become less so at the last in a series of identical stimuli, or be activated by the absence of a further event. It is proposed that the potentials are due to a higher order of neurone which automatically responds to the occurrence of a "mismatch" between the immediate sound and an image of that which was previously present, encoded in a short-term sensory store. In addition to frequency content and interaural delay, the image must contain information about the temporal modulation pattern of the sound over the previous few seconds.

Tactile interference differentiates sub-components of N20, P20 and P29 in the human cortical surface somatosensory evoked potential

Somatosensory evoked potentials (SEPs) to median nerve stimulation were recorded from up to 64 locations on the exposed cortical surface in 19 patients undergoing intracranial surgery for epilepsy and/or tumour removal. In view of previously described 'interference' effects on scalp SEPs, a continuous light tactile stimulus was applied to the palm and the first 3 digits of the stimulated hand in order to try to differentiate components due to input from cutaneous and other sensory receptors. The first cortically generated potentials, N20 at postcentral locations and P20 precentrally, could each be resolved into 2 subcomponents separated by about 2.5 msec. The later subcomponent was consistently the more attenuated by the interfering stimulus and is postulated to be due to input from rapidly adapting cutaneous mechanoreceptors. The earlier subcomponent could be due to input from muscle afferents or from slowly adapting cutaneous receptors which the interfering stimulus would have activated to a lesser degree. In 2 cases the P29 potentials recorded from regions of the postcentral gyrus were dissociated. In one case the potentials recorded at adjacent electrodes were attenuated to differing degrees, and in the other the effect was maximal at different locations when the thumb, index and middle fingers were stimulated separately. The method therefore appears capable of distinguishing regions of the postcentral gyrus concerned with cutaneous input from different parts of the hand.

Microscopy of bone cells, bone tissue, and bone healing around implants

Newer methods of scanning microscopy using both light and electrons are particularly relevant to the study of bone cells, bone matrix organization, matrix mineralization, bone modeling and remodeling, and the adaptation of cells and matrix to implants. Most of such studies are conducted on retrieved implants, at least after the death of the related tissue. Because the retention of the tissue-implant relationship in such preserved tissue is crucial for critical evaluation of the implant, methods based on the study of flat surfaces of embedded tissue blocks are very important. Using electrons, the backscattered electrons in a scanning electron microscope can be employed to evaluate mean atomic number (density) and cathodoluminescence can identify polymers and fluorescent labels. Using light, confocal microscopical techniques permit the examination of layers deep to the block face. Confocal reflected and fluorescence methods allow the study of cell behavior upon both transparent and opaque substrates in the laboratory. Examples of the above are presented and interpretation problems discussed. Current experiments are aimed at enabling the study of bone wound healing and bone adaptation to implanted materials in vivo, through the implantation of optical quality windows and/or newly conceived and designed microscopical objective lenses.

Effect of retinoic acid on the resorptive activity of chick osteoclasts in vitro

Mixed cell suspensions mechanically isolated from the long-bones of day 20 prehatch chicks were cultured for 24 h on bone and sperm whale dentine slices in the presence of 0, 10, 100, and 1000 nM retinoic acid (RA). Significant inhibitions in the numbers of discrete lacunae resorbed per dentine slice, and in the ratio of lacunae per tartrate-resistant acid phosphatase-positive multinuclear cell were observed with all concentrations of RA studied. Semi-automated, 3-dimensional analysis of 733 pits was performed on one series of experiments using a tandem scanning (confocal) microscope, interfaced to an image analyzing computer. The majority of lacunae were small and unilocular; the plan areas of 90% of control pits were below 500 microns 2. Small but statistically significant increases in lacunar areas, but not mean or maximum depths or volumes, were observed in the presence of 10 and 100 nM RA; however, these changes were much smaller than the magnitude of the decrease in pit numbers. Thus, the overall effect of RA in this system was inhibitory. Our findings contrast with the well known stimulatory action of retinoids on bone resorption both in vivo and in organ culture, but may parallel the inhibitory effects of prostaglandins observed in disaggregated osteoclast systems.

Potentials evoked in human and monkey cerebral cortex by stimulation of the median nerve. A review of scalp and intracranial recordings

Somatosensory evoked potentials (SEPs) are generated in afferent pathways, subcortical structures and various regions of cerebellar and cerebral cortex by stimulation of somatic receptors or electrical stimulation of peripheral nerves. This review summarizes current knowledge of SEPs generated in cerebral cortex by stimulation of the median nerve, the most common form of stimulation for human research and clinical investigations. Major sources of data for the review are intracranial recordings obtained from patients during diagnostic or neurosurgical procedures, and similar recordings in monkeys. Short-latency cortical SEPs in the 20-40 ms latency range consist of P20 and N30, recorded from motor cortex and frontal scalp; P25 and N35, recorded from cortex near the central sulcus and central scalp; and N20 and P30, recorded from somatosensory cortex and parietal scalp. Several lines of evidence including cortical surface and intracerebral recordings, neuromagnetic recordings and lesion studies in humans and monkeys, strongly support the conclusion that these potentials are generated in contralateral somatosensory cortex in areas 3b and 1, in contrast to the conclusion of many previous studies that SEPs recorded from the frontal scalp are generated in motor cortex and other frontal lobe areas. These potentials are primarily mediated by cutaneous afferents of the dorsal column-medial lemniscal system; the contribution of muscle afferents has not been completely resolved but appears to be small. There is currently no evidence that short-latency SEPs are generated in cortex other than primary somatosensory cortex. Recordings from the vicinity of the second somatosensory area, from the supplementary motor and sensory areas and from surface cortex other than sensorimotor cortex have not detected reliable short-latency activity, although some of these regions generate long-latency potentials. Consequently, short-latency SEPs recorded from the scalp are similar to those recorded from the surface of sensorimotor cortex. Old World monkeys such as Macaca mulatta and M. fascicularis provide an excellent model for human short-latency SEPs. All the potentials described above in humans have corresponding monkey analogues, with similar distributions over the cortical surface. The squirrel monkey, a New World species, exhibits the same potentials, but due to the different morphology of sensorimotor cortex, the surface distribution of SEPs is quite different.

The pathophysiology of acute optic neuritis. An association of gadolinium leakage with clinical and electrophysiological deficits

Eighteen patients with acute optic neuritis underwent optic nerve magnetic resonance imaging (MRI) before and after injection of gadolinium-diethylene triamine pentacetic acid (Gd-DTPA). Ten were re-examined 4 weeks later. Leakage of Gd-DTPA across the blood-optic nerve barrier was a consistent finding in the acute lesion, and its presence was associated with abnormal visual acuity and colour vision, retro-ocular pain on eye movement, and afferent pupillary defect, and a reduced amplitude of the P100 component of the visual evoked potential. Gd-DTPA leakage had ceased in 9/11 nerves when restudied 4 wks later, and this evolution was associated with improved visual acuity and an increased P100 amplitude. Leakage is likely to reflect inflammation, and we conclude that the latter plays an important part in the production of conduction block and clinical deficit, and that its resolution is an important step in clinical remission from acute episodes of demyelination.

Intraocular pressure asymmetry in a population tested with the Pulsair non-contact tonometer

Intraocular pressure asymmetry as measured by noncontact tonometry (NCT) was analysed in a population of 874 individuals aged over 50 years. In both males and females the intraocular pressure (IOP) measured in the right eye exceeded that of the left. Pressure asymmetry followed a normal distribution in a population subgroup known to have normal fields, discs and pressures. The 95% confidence intervals for the equation R IOP--L IOP in normals were 0.63+ or -5.46 mmHg when the mean of four pulses per eye were used to calculate the IOP, increasing to 0.80+ or -6.56 mmHg for two pulses per eye (thus expanding the limits by 20%). The range of asymmetry for NCT in normals therefore exceeds that reported for Goldmann applanation tonometry. Asymmetry was greater in females than males. Knowledge of the normal range of IOP asymmetry in each sex will help glaucoma screeners using NCT in their decision as to when to refer. A minimum of four pulses per eye should be used to assess the IOP when screening.