The glucose challenge test: different drink dilutions.
Explore the source record for details and available documents.
Administration, Oral↗
Biomedical subjects
R Davey
Publications and source records attributed to R Davey.
Pseudobacteraemia with Pseudomonas fluorescens.
Explore the source record for details and available documents.
Bacteremia↗
ATP-sensitive K+ channels mediate vasodilation produced by lemakalim in rabbit pulmonary artery.
Tension recording and the patch-clamp technique were used to determine the mechanism underlying vasodilation produced by lemakalim in the rabbit pulmonary artery. Lemakalim produced relaxation of precontracted muscle strips that was inhibited by glibenclamide and tetrapentylammonium ions but not by 2 mM tetraethylammonium (TEA) ions. In single cells dialyzed with 1 mM ATP, lemakalim (10 microM) hyperpolarized cells by approximately 13 mV and activated a time-independent K+ current, averaging only 6.5 pA at -50 mV. Glibenclamide reversed both of these membrane effects of lemakalim but not the lemakalim-induced block of an outward current seen above -20 mV. ATP depletion hyperpolarized cells and selectively unmasked a background K+ current, which was sensitive to glibenclamide but not to TEA, with properties similar to the current activated by lemakalim during membrane hyperpolarization. Furthermore, when intracellular ATP concentrations were varied, a clear correlation was revealed between ATP levels and the magnitude of the depolarization or hyperpolarization seen with either glibenclamide or lemakalim, respectively. These results provide direct evidence that the background current is carried by ATP-sensitive K+ channels rather than by large-conductance Ca(2+)-activated K+ channels and that it underlies the hyperpolarization and relaxation to lemakalim.
Adenosine Triphosphate↗
Isoprenaline reverses the slow force responses to a length change in isolated rabbit papillary muscle.
An alteration in the length of isolated cardiac muscle produces an immediate change in twitch force, then a slow further change in the same direction. We have found that the slow changes in force in rabbit papillary muscles are blocked or reversed by the beta-agonist, isoprenaline (1 microM). The abolition of the slow responses by isoprenaline was not due to saturation of the myofibrils with Ca2+, as the blockade continued if the extracellular [Ca2+] was reduced in the presence of isoprenaline so that twitch force was < 50% maximal. Ryanodine (1 microM) did not block the slow responses, suggesting that the sarcoplasmic reticulum does not mediate the responses. These results suggest that changes of intracellular [cAMP] may mediate, or at least modulate, the slow force responses to a length change in cardiac muscle.
Animals↗
Combined zidovudine and interferon-alpha therapy in patients with Kaposi sarcoma and the acquired immunodeficiency syndrome (AIDS)
STUDY OBJECTIVE: To evaluate the toxicity and potential clinical efficacy of combined therapy with zidovudine and interferon-alpha for patients with Kaposi sarcoma and the acquired immunodeficiency syndrome (AIDS). DESIGN: Nonrandomized, open trial study. SETTING: Outpatient clinic of a government referral-based research hospital. PATIENTS: Volunteer sample of 39 patients with human immunodeficiency virus (HIV) infection and Kaposi sarcoma. INTERVENTIONS: Patients received zidovudine, 250, 100, or 50 mg orally every 4 hours; 6 weeks after interferon-alpha was begun at a dose of 5 million U/d, and the dose was increased every 2 weeks until a maximum tolerated dose was determined. Patients then received the maximum tolerated dose of the combination for a minimum of 12 weeks before formal efficacy evaluations. MEASUREMENTS AND MAIN RESULTS: In the dose-escalation phase, the ability to tolerate interferon-alpha was clearly related to the zidovudine dose. Of the 13 patients receiving 250 mg of zidovudine, only 1 patient was able to tolerate at least 10 million U/d of interferon-alpha. Of the 12 patients receiving 100 mg of zidovudine, 8 tolerated 10 million U/d, 5 tolerated 15 million U/d, and none tolerated higher doses. Of the 12 patients receiving 50 mg of zidovudine, 8 tolerated 10 million U/d, 7 tolerated 15 million U/d, and 6 tolerated 20 million U/d or more. Dose-limiting toxicities included neutropenia (57%), fatigue (16%), thrombocytopenia (14%), and hepatic dysfunction (10%). Of the 22 patients who received a stable dose of both drugs for 12 weeks, 11 patients had a complete or partial tumor response and 8 showed an anti-HIV effect. Peak serum levels of interferon-alpha (32 to 250 U/mL) and zidovudine (0.40 to 3.85 microM) were in the ranges previously shown to be synergistic against HIV. CONCLUSIONS: Combination therapy with zidovudine and interferon-alpha can be administered to patients with HIV infection and Kaposi sarcoma in doses that effect antiviral and antitumor responses; it appears to have a potential role in managing such patients.
Acquired Immunodeficiency Syndrome↗
Autoradiographic localization of 3H-dextromethorphan binding sites differs from NMDA.
Explore the source record for details and available documents.
Animals↗
The mechanism of action of capsaicin on sensory C-type neurons and their axons in vitro.
The selective excitant and neurotoxic action of capsaicin on vagal sensory neurons in the rat has been investigated in vitro using three techniques: extracellular recording of compound spike potentials from the whole nerve; intracellular recording from ganglion cells using single-electrode current and voltage clamp; and electron microscopy of the nerve and nodose ganglion. Capsaicin (0.1-10 microM) depolarized vagal sensory C fibres and cell bodies, and produced an increased conductance. The conductance increase appeared to be due to an increased permeability to sodium and calcium, plus a secondary increase in potassium (and perhaps chloride) conductance consequent upon calcium entry. The early entry of calcium seems to be a significant priming event in the neurotoxic process, since dramatic ultrastructural changes take place within a few minutes of capsaicin application, which are minimized by removing extracellular calcium ions. The observations indicate that in sensory C neurons capsaicin opens a conductance of limited specificity and that a resultant large calcium entry is closely involved in the rapid development of cell injury.
Animals↗
The heterogeneity of arylsulphatase-A and arylsulphatase-B in normal human urine and urine from cancer patients.
Arylsulphatase-A and arylsulphatase-B heterogeneity in normal and cancer patient urine was investigated using high resolution agarose isoelectricfocusing. Normal urine contained up to nine forms of arylsulphatase-A activity with isoelectric points from 4.45 to 5.43 and at least 5 forms of arylsulphatase-B between 8.58 and 9.15 along with a broad zone of activity between pH 6.5 and 7.6. Although cancer patients had significantly higher levels of arylsulphatase-A and arylsulphatase-B activity, their pattern of activity was essentially the same as for the normals with only minor quantitative differences in some peaks.
Cerebroside-Sulfatase↗
Macrodantin: a cautionary tale.
Nitrofurantoin, one of the antimicrobial agents which should be chosen for the prophylactic treatment of recurrent urinary tract infection, may be prescribed in the conventional form or, alternatively, as macrocrystals. The latter form (Macrodantin) is reported to engender less gastrointestinal intolerance but it can produce the same adverse effects as the conventional form--liver damage, acute and chronic pulmonary reactions, peripheral neuropathy, blood dyscrasias and allergic reactions--and does so just as rapidly and floridly; one such case is reported here.
Female↗
Serum galactosyltransferase isoenzyme patterns of cancer patients with liver involvement.
The level of galactosyltransferase activity was measured in the serum of 220 patients with a variety of solid tumours. There was a significantly greater proportion of patients with elevated galactosyltransferase in the group with metastatic disease (43%) than for the group with localised disease (16%). Galactosyltransferase was elevated in 69% of patients with liver metastasis compared to 32% of patients with metastatic disease at sites other than liver and this difference was also significant. High resolution agarose isoelectric-focusing was used to determine the 'isoenzyme' pattern of serum galactosyltransferase of 6 patients with liver metastasis and 2 patients with primary hepatoma and these were compared to those of 6 patients with similar primary tumours without liver involvement. There were no qualitative differences in the patterns from the two groups. The average peak height for each of the 19 peaks of activity identified was generally higher in the group with liver involvement, except for those peaks known to contain little or no attached sialic acid. Liver involvement appears not to contribute in any specific way to the altered pattern of serum galactosyltransferase often seen in patients with solid tumours. The tumour rather than the liver is therefore the most likely source of these alterations.
Carcinoma, Hepatocellular↗
Lymphocyte migration in the adoptive transfer of EAU.
Experimental autoimmune uveoretinitis (EAU) was transferred into naive male Lewis rats using 1 X 10(8) indium-111 labeled lymphocytes from syngeneic donors immunized with S-antigen. The migration of the lymphocytes was monitored by gamma camera imaging and by determining the accumulation of radioactivity in selected organs. The majority of the cells leave the peritoneal cavity within 24 hr and migrate to the liver, spleen, and thymus. Only a small fraction of the labeled cells reach the eye. However, there were significantly more labeled cells present in eyes that developed EAU as compared with controls using lymphocytes sensitized against bovine serum albumin. These results indicate the adoptive transfer of EAU is a complex process in which only a small number of transferred cells actually reach the eye to induce uveoretinitis.
Animals↗
Release of galactosyltransferase from peritoneal macrophages during acute inflammation.
Peritoneal cells harvested from mice injected with Salmonella enteritidis or thioglycollate released large amounts of galactosyltransferase (GT), but not sialyltransferase, into their culture supernatants. Maximum release of GT (using ovalbumin as acceptor) occurred from cells harvested 2-4 days after primary injection, but little GT was released from cells elicited by a secondary injection of salmonella or ovalbumin in sensitised mice or during intraperitoneal allogeneic reactions. Enzyme release in culture did not parallel GT levels in serum. Most enzyme was released by large, poorly adherent, macrophage-enriched, Fc receptor-bearing peritoneal cells of low density. Normal monocytes, bone marrow cells, and platelets also produced large amounts, and normal spleen cells or polymorphonuclear leukocytes moderate amounts, of GT. Lymphocytes, dead cells, mast cells, red blood cells, or whole populations of lymph node and thymus cells released very low levels of enzyme. Very little GT was bound to the cell surface and was not passively absorbed from serum or platelets. Release of GT was prevented at 4 degrees C but was not markedly affected by a variety of metabolic inhibitors except pretreatment of the cells with thrombin, which increased release and trypsin which decreased release.
Animals↗
Persisting illness and fatigue in adults with evidence of Epstein-Barr virus infection.
Clinical, serologic, virologic, and immunologic evaluations for 31 adults with chronic illness and fatigue suggested that 23 had persisting Epstein-Barr virus infection. Among these 23 patients, cellular immune mechanisms were generally normal, but 4 had mild immunoglobulin deficiencies. However, 20 patients had abnormal serologic profiles specific for Epstein-Barr virus shown by significantly elevated titers of antibodies to the viral capsid antigen or early antigen, or by a deficiency of late-appearing antibodies. In 11 of 15 patients tested, circulating immune complexes were found. Circulating interferon was not found in 18 patients tested, but the activity of 2-5 oligoadenylate synthetase, an interferon-induced enzyme, was increased in 5 patients studied. Of 19 patients, 18 had persisting suppressor T-cell activity typically found in patients recovering from acute infectious mononucleosis. We believe that the Epstein-Barr virus may be associated with chronic illness in adults.
Adolescent↗
The heterogeneity and acceptor specificity of human serum galactosyltransferase.
Human serum was fractionated by high resolution agarose isoelectricfocusing and the galactosyltransferase activity profile was determined using the ovalbumin, mucin, glucose and N-acetylglucosamine acceptor assays. The four acceptors gave very similar activity profiles. There were minor quantitative differences in some of the 12 or more peaks of activity detected and the only qualitative difference between them was a minor peak at pH 3.90 (2% of the total activity) which reacted only with the mucin acceptor. This suggests that most of the isoenzymes of human serum galactosyltransferase have broad and similar acceptor specificities and that the heterogeneity seen in serum cannot be accounted for by acceptor-specific forms of the enzyme.
Galactosyltransferases↗
The analysis of soluble galactosyltransferase isoenzyme patterns using high resolution agarose isoelectricfocusing.
A high resolution method has been developed to separate the isoenzymes of galactosyltransferase by combining isoelectricfocusing (IEF) in 245 mm long agarose gels with a highly sensitive enzyme activity assay. The resolution and sensitivity is such that the isoenzyme pattern of 10 microliters human serum can be resolved. Using this method normal human serum was shown to contain at least 12 isoenzyme forms of galactosyltransferase, the major forms having isoelectric points of 4.33, 4.43, 4.51, 4.61, 4.74, 4.87, 4.96, 5.16 and 5.23. Part of the isoenzyme pattern complexity is due to sialylation of some isoenzymes. Alpha-lactalbumin-affinity chromatography, a method widely used in the purification of galactosyltransferase, causes a preferential purification of some of the isoenzyme forms.
Ascitic Fluid↗
Malacoplakia of the female genital tract.
Malacoplakia is an uncommon chronic granulomatous inflammation which most frequently involves the urinary bladder of middle-aged women and rarely affects the genital tract. In this paper 10 cases of female genital malacoplakia are reviewed, seven of which have been reported previously in the literature. Genital malacoplakia usually occurs in women 60 years of age or older and most frequently affects the vagina. Vaginal bleeding is a common presenting complaint and the lesion may simulate a malignancy. Four of the 10 patients were receiving corticosteroids at the time of diagnosis. Escherichia coli was cultured from urine or from the lesion itself in half of the cases. The disease appears to be an acquired defect in bactericidal function of histiocytes. Antibiotic therapy and surgical excision are effective, although a recurrence developed in one patient and was successfully re-excised.
Aged↗
Genetic regulation of mammalian glucuronidase.
Explore the source record for details and available documents.
Animals↗
Differential effect of hypophysectomy on the synthesis of beta-glucuronidase and other androgen-inducible enzymes in mouse kidney.
The levels of several androgen responsive enzymes including beta-glucuronidase, alcohol dehydrogenase, D-amino acid oxidase and arginase, were compared in kidneys of normal and hypophysectomized female mice after treatment with testosterone. While hypophysectomy did not alter the basal level of glucuronidase, the androgen-mediated accumulation of kidney beta-glucuronidase was greatly decreased in hypophysectomized mice. Measurements of the rate of synthesis of glucuronidase showed that after androgen treatment the enzyme was synthesized in kidney of hypophysectomized mice at only 5% the normal rate. Glucuronidase activity in seven other organs was not appreciably affected by treatment with androgens or by hypophysectomy. Unlike the effect of hypophysectomy on kidney glucuronidase, there was no reduction in the accumulation of alcohol dehydrogenase or D-amino acid oxidase in kidney of hypophysectomized mice after androgen treatment. Hypophysectomy caused a large reduction in kidney arginase activity. However, subsequent administration of testosterone restored much of this activity. It is concluded that there are at least two mechanisms by which androgens increase enzyme activity in kidney. The normal increase in activity or rate of synthesis of beta-glucuronidase following androgen administration requires pituitary hormones and/or products of these hormones, while the increase in activity of enzymes like alcohol dehydrogenase and D-amino acid oxidase does not require pituitary hormones.
Adrenalectomy↗