Health care in a deprived community.
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Health Promotion↗
Biomedical subjects
J Richards
Publications and source records attributed to J Richards.
Maintenance of normal rat mammary epithelial cells by insulin and insulin-like growth factor 1.
Normal rat mammary epithelial cells were cultured within a rat tail collagen gel matrix formed under improved conditions for controlling pH and osmolarity. Under these conditions, growth can be maintained for up to 3 weeks with a 10- to 15-fold increase in cell number. The cells grow in response to prolactin, progesterone, epidermal growth factor, and cholera toxin, in a medium of DME: Ham's F12 supplemented with BSA and insulin at 10 micrograms/ml. When the insulin concentration was reduced to more physiological levels (10 ng/ml) the cells did not grow. However, at these more physiological concentrations it could be shown that insulin had a concentration-dependent effect on the maintenance of the cells with an optimum concentration around 25 ng/ml. The cells could be maintained in hormone-supplemented medium with low levels of insulin in a quiescent state for up to 14 days. The high levels of insulin needed for optimal growth could be replaced by insulin-like growth factor 1 (IGF-1) at much lower concentrations (25-50 ng/ml). The superphysiological level of insulin required for optimum growth is probably due to its acting weakly through an IGF-1-mediated growth-promoting mechanism. Insulin's effect on cell maintenance occurs at physiological levels and may better reflect its role in mammary cell growth.
Animals↗
Recurrence of Listeria monocytogenes meningitis.
A case of Listeria monocytogenes meningitis in a 3-year-old boy which relapsed after chloramphenicol treatment is described. The patient was subsequently successfully treated with ampicillin and gentamicin and made a complete recovery. In vitro studies confirmed the inadequacy of chloramphenicol therapy. The value of combination therapy, as evidenced by chessboard and killing-curve techniques with the strain, is discussed.
Ampicillin↗
Evaluation of a rapid method for identifying Branhamella catarrhalis.
The speed and precision of hydrolysis of tributyrin to butyric acid as a test to detect Branhamella catarrhalis were evaluated. The test proved consistently reliable in the identification of strains and correctly differentiated B catarrhalis from Neisseria sp. The combination of Gram stain, oxidase, and catalase tests to tributyrin hydrolysis provides a means of positive same day identification of B catarrhalis.
Bacteriological Techniques↗
Biological and immunological characterization of cleaved and 16K forms of rat prolactin.
A cleaved form of rat PRL (rPRL) has been reported to exist in the pituitary gland and to be the main product of PRL proteolysis by its target tissues. A 16K fragment derived from cleaved PRL (cPRL) has mammary mitogenic activity in rats in vivo, and we found that both cleaved and 16K PRLs are capable of binding to hepatic PRL receptors. To analyze the functional significance of cleaved and 16K PRLs, ample amounts of cPRL were generated by incubation of 24K rPRL in vitro with a 25,000 X g rat mammary gland pellet. cPRL was reduced (2-mercaptoethanol), and the 16K and 8K fragments were separated by gel filtration. The purity of the cleaved and 16K samples was established by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and their mitogenic [pigeon crop-sac, Nb2 lymphoma cell, and mammary cell bioassays (BAs)], lactogenic (casein BA), and immunologic (PRL RIA) activities were determined. cPRL had the same mitogenic activity, but half the immunoactivity, as intact PRL. The 16K fragment was biologically active in all assays. Its estimated mitogenic and lactogenic potencies were 65% and 10% those of the 24K PRL, respectively, and it had only 2% the immunoactivity of the intact hormone. Thus, the 16K fragment had higher BA to RIA ratios than cleaved or intact 24K PRLs. The functional significance of 16K PRL may have been underestimated owing to its low RIA activity.
Animals↗
The lack of effect of phenol red or estradiol on the growth response of human, rat, and mouse mammary cells in primary culture.
Normal and neoplastic mammary cells from both human and rodent sources grow in culture in response to a number of hormones and growth factors. However, with the exception of a few human tumor lines, a consistent growth-promoting effect of estrogens on mammary cells has not been observed. Mammary cells can be shown to respond to other hormones and factors, such as PRL, hydrocortisone, and epidermal growth factor. Recent observations suggest that the pH indicator dye phenol red, found in most media, may be masking any exogenous estrogenic effects by acting as a weak estrogen. To test this possibility, we reexamined the effects of estradiol (E2) and the antiestrogen keoxifene on the growth of normal human, mouse, and rat mammary cells in the absence of phenol red. Primary cultures of these mammary cells were grown within a rat tail collagen gel matrix in a serum-free medium made up of Ham's F-12 and Dulbecco's Modified Eagles' medium (1:1) with and without phenol red. The medium was supplemented with various hormones and growth factors. These supplements were selected for each cell type to produce a variety of conditions from nongrowing to rapidly growing. The effects of E2 (10(-10)-10(-8) M, keoxifene (10(-9)-10(-6) M), and phenol red on growth under these various conditions were examined. Phenol red had no effect on growth, and its absence did not restore a response to E2. Keoxifene, in the presence or absence of E2, also had no effect on growth. Although E2 had no effect on growth, it was able to induce a 150% increase in the progesterone receptor levels in normal mouse mammary cells in culture, indicating that the cells retain their capacity to respond to E2. This work supports the idea that the effect of estrogens on growth in vivo may be mediated through some other factor(s).
Animals↗
Role of arachidonic acid release in the G2 delay induced by tumor promoter TPA in HeLa cells.
The tumor promoter TPA2 (12-O-tetradecanoylphorbol-13-acetate) has been shown to exhibit a radiomimetic activity on the cell cycle of HeLa cells (V. Kinzel, J. Richards, and M. Stöhr (1980) Science 210, 429). The response includes a delay of cells in G2 phase. The relation between TPA-induced release of arachidonic acid (AA) and the inhibition in G2 phase was studied. Exogenous AA (greater than 10(-4) M; in presence of 10% serum) is shown to delay HeLa cells in G2 and to enhance the effectiveness of TPA in this respect. The inhibition of the TPA-induced AA liberation by fluocinolone acetonide, however, does not influence the TPA-effected G2 delay. The diacylglycerols 1,2-dioctanoyl-glycerol and 1-oleoyl-2-acetylglycerol delay HeLa cells in G2 but without major stimulation of AA liberation. On the basis of the data it is concluded that AA released from HeLa cells due to the action of TPA is not involved in the TPA-induced delay of cells in G2 phase.
Arachidonic Acid↗
Stiffness in healing fractures.
Methods are available for direct measurement of stiffness in fracture healing. The methods are generally dissimilar in their technique and in some cases the applied assumptions are contrary to the principles of basic mechanics. External fixation provides the potential for direct measurement of fragment end movement, and techniques associated with this type of treatment have been applied in Belgium on more than 500 patients. These results are generally presented as decreases in flexure of the fixator bar due to constant loading, representative of increases in fracture stiffness. The same procedure is adopted to internal fixation plates and also direct strain gauge application to the healing bone--there are obvious complications due to electrical connections in the latter case. The biomedical changes occurring during healing are illustrated by the work at Cardiff where a biphase characteristic has been identified. The method used has the disadvantage in requiring the removal of the fixator for the application of the stiffness sensor recording deflection and rotation. The advantages of the technique include the more precise modeling of the bending characteristic of the tibia (the results refer to this particular skeletal element). The experimental studies at Oxford show evidence of enhanced osteogenesis when controlled intermittent deformation is applied in a cyclic manner. In a group of some 50 patients treated with induced micromovement, there is evidence that the rate of increasing fracture stiffness would allow removal of the fixator at 15 weeks compared with 24 weeks in the group with rigid fixation. The exact technique of measuring fracture stiffness has to be compared with other noninvasive test methods which include radiological examination, ultrasound, resonant vibration, and modal analysis. Many of these methods are based on linear elastic relationships which are inadequate to describe the anisotropic behavior of bones. The vibration analysis techniques are showing potential as clinical tools, and collaboration within the European community is directed towards a correlation between invasive and noninvasive methods of fracture monitoring.
Biomechanical Phenomena↗
Fictitious calculi and human calculi with foreign nuclei.
The correlative approach employing polarized light microscopy, x-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction and energy dispersive x-ray microanalysis proves to be very useful in identifying fictitious calculi and genuine human calculi with foreign body nuclei. The common artifacts as reported in the literature and observed also by us were minerals, vegetable and plant seeds, cereals, sand grains and sea shell fragments. Two interesting cases involving foreign body nuclei have been reported: one urinary calculus containing a piece of plastic-coated titanium foil in the center; one nasal calculus with a nut as a nucleus. Another common cause for foreign body nucleation is iatrogenic: intrauterine devices, catheters, suture materials and even surgical staples have been reported in the literature to be potent nidi for calculus formation. These cases remind us of the important fact that our body fluids are supersaturated with respect to calcium phosphates and occasionally to other compounds. Hydroxyapatite crystals are readily nucleated by foreign bodies. Whitlockite is involved if the fluid Mg/Ca ratio is in a suitable range, brushite if the fluid is acidic and struvite if there is urea-splitting infection. In urine and other fluids, calcium oxalate and uric acid crystals contribute to the calculus growth.
Calculi↗
Resonances in the low-energy 13C+13C spectrum.
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Journal Article↗
Variation and adaptation of Pseudomonas aeruginosa toxicity to HeLa cells and fibroblasts.
The toxic components of supernatants from Pseudomonas aeruginosa cultures directed against HeLa cells and Staphylococcus aureus were evaluated with the aim of discovering interactions. Supernatants of eight different strains of P. aeruginosa were assayed for cytotoxic activity. All were active against HeLa cells; seven were toxic for S. aureus. On repeated suspension of P. aeruginosa in 0.9% sodium chloride solution, a shift from HeLa cell toxicity to staphylococcal lytic activity occurred along with a change of toxic activity from a high (50,000 +/- 5,000) to a low (8,000 +/- 400) molecular weight (MW) range on gel filtration. Addition of protein to the minimal medium of cultures producing material toxic only for S. aureus reactivated the generation of HeLa cell-toxic material. Cultivation of P. aeruginosa in the presence of HeLa cells and a chloramphenicol supplement produced suppression of the generation of material toxic for S. aureus but facilitated that of HeLa-toxic material of high MW. Adaptation of toxicity against fibroblasts developed only on cocultivation of P. aeruginosa together with S. aureus and in the presence of fibroblasts. Under these conditions a strong lytic activity for S. aureus appeared, even in the presence of chloramphenicol. Chloramphenicol caused the material toxic for fibroblasts to elute at a low MW well separated from that toxic for HeLa cells. In contrast to the high-MW toxic substances, the low-MW material did not induce antibodies after injection into rabbits. This may explain failures of vaccination against P. aeruginosa infection and of serum therapy of homologous sepsis in humans.
Bacterial Toxins↗
Analysis of heart rate and respiratory patterns in sudden infant death syndrome victims and control infants.
Retrospective analyses of patterns of breathing and heart rate variability obtained by visual inspection and spectral analysis of ECG and respiratory activity have provided markers associated with subsequent death in a referred population of infants at high risk for sudden infant death syndrome (SIDS). Such markers include breathing patterns characterized by excessive apneic pauses and periodic breathing, heart rate spectra characterized by increased low frequency oscillations, and respiratory activity spectra characterized by a widened "bandwidth" during regular breathing. To test whether such measurements could distinguish SIDS cases and randomly selected controls from a population study the data from 10 cases and 100 age-matched control subjects were analyzed blind. The code was disclosed after completion of the analysis. We found that none of the markers served to distinguish the SIDS cases from the controls in the population at large. This observation may indicate important physiological differences between infants destined to die in the referred high risk population and infants who die of SIDS at large. The possible reasons for our inability to identify the group of SIDS in the general population, as compared to the group of deaths in the referred high risk group are: (1) different disease processes in the two groups, (2) difference responses to the same disease process in the two groups, (3) a response reflecting the psychosocial setting of the referred high risk population, (4) methodological differences between this and previous studies. We conclude that these markers are not of value in screening the population at large.
Heart Rate↗
Heterogeneity in the hormonal responsiveness of clones derived from the 13762NF rat mammary tumor.
The transplantable hormone-responsive rat mammary adenocarcinoma 13762NF was dissociated with collagenase and hyaluronidase. Cells were cloned directly or lines were established from mass cultures and cells from these lines were cloned. Clones differed in cellular morphology, colony morphology on plastic or in collagen gel, growth rate, growth response to hormones, and hormone receptor levels. Growth response to prolactin, estradiol, progesterone, cortisol, and epidermal growth factor (EGF) was determined by culturing the cells within collagen gel and using a serum-free medium base of DME/F12 (1:1) with insulin, linoleic acid, and BSA. The clones varied in their hormone responses, with all 20 of the clones tested responding to cortisol in combination with EGF. Some clones would respond to EGF, cortisol, or progesterone when used alone. None of the clones tested could be stimulated by prolactin or estradiol. Receptor levels for estradiol, progesterone, glucocorticoids, and EGF were assessed in 3 selected clones differing in their hormone responsiveness. Receptor levels appeared to correlate with hormonal sensitivity. Selected clones transplanted into female F344 rats produced carcinomas with histopathologies similar to the original tumor.
Adenocarcinoma↗
Nursing practice in ambulatory care.
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Ambulatory Care↗
Determination of cortisol and cortisone in urine using high-performance liquid chromatography with UV detection.
The application of reversed-phase gradient high-performance liquid chromatography with UV detection to the determination of cortisol and cortisone in 24-h urine samples is described. The method employs Sep-pak C18 cartridges for the part-purification and concentration of the corticosteroids, with sample enrichment at the head of an HPLC pre-column and separation using water/acetonitrile gradient. The internal standard is 6alpha-methylprednisolone. Measurement of both cortisone and cortisol provides further information on adrenocortical function. 24-hour excretion rate data from normal subjects are reported.
Journal Article↗
Bacteroides fragilis isolated post mortem from an abscess in a myocardial infarct.
An unusual case of an abscess complicating a myocardial infarct is described. Similar cases reported so far are reviewed, with special attention to modes of presentation, possible sources of infection and complications.
Abscess↗
Mechanistic aspects of the delay in the G2 phase of the cell cycle caused by tumor promoter 12-O-tetradecanoylphorbol-13-acetate in HeLa cells.
In order to gain an insight into the nature of the radiomimetic activity by which the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) alters cell cycle parameters in HeLa cells, possibilities of modifying the TPA-induced G2 block and recovery from it were studied. TPA-induced G2 blockage was analysed by counting mitotic figures. It was not influenced by hydroxyurea (10(-3) M) thus indicating that it is independent of DNA synthesis. TPA-induced decrease of mitotic activity occurred faster than that caused by cycloheximide (10(-5) M) indicating that the TPA-sensitive transition point in G2 is closer to mitosis than that for cycloheximide. Superoxide dismutase, catalase, alpha-tocopherol, the radioprotector S-(2-aminoethyl)isothiuroniumbromide.HBr (AET), caffeine and indomethacin and eicosatetraynoic acid (ETYA), both inhibitors of oxygenases in the arachidonic acid cascade, were not capable of reducing the TPA-induced G2 response. Under certain conditions small concentrations of AET (10(-8) M) and ETYA (10(-8) M) appeared to improve recovery slightly. Mannitol and sorbitol, however, both hydroxyl radical scavengers at 0.1 M concentration reduced TPA-effectiveness to a large degree (0.1 M D- and L-mannose were ineffective). Dimethylsulfoxide (0.1 M), another hydroxyl radical scavenger, was ineffective.
5,8,11,14-Eicosatetraynoic Acid↗
Doctor-patient communication in surgery.
The efficiency of communication between junior hospital doctors and 77 general surgical patients was assessed by using standardized questionnaires before and after the doctor/patient interview on both the patient and the house doctor. Patients were better informed about their illness than their surgery, and doctors wrongly estimated patients' knowledge in 41% of cases. Self-reported preoperative anxiety of patients was low and was estimated wrongly by house doctors in 58% of cases. In 52% of cases house doctors were considered by patients to be the most important source of information, but patients had little comprehension of the seniority of other doctors. Although 60% of patients were satisfied with the communication, the majority complained of lack of information concerning convalescence, postoperative pain and routine ward procedures.
Adolescent↗