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Biomedical subjects

G Gill

Publications and source records attributed to G Gill.

143 records · Page 8Linked to original sources
PubMed1976

The use of affinity chromatography in purification of cyclic nucleotide receptor proteins.

Biospecific affinity chromatography has been used to purify specific cyclic AMP and cyclic GMP receptor proteins. Several variables are important for successful purification of the cyclic AMP receptor protein, the most critical being the length of the aliphatic spacer side arm. 8-(2-Aminoethyl)-amino-cyclic AMP coupled to the aliphatic spacer side arm. 8-(2-Aminoethyl)-amino-cyclic AMP coupled to agarose specifically retains the cyclic AMP receptor protein by interaction with the immobilized nucleotide. Binding of the cyclic AMP receptor subunit of cyclic AMP-dependent protein kinase to the immobilized nucleotide results in dissociation of the catalytic protein phosphokinase subunit which is not retained. The retained cyclic AMP receptor protein is subsequently eluted by cyclic AMP. Homogeneous cyclic AMP receptor protein prepared from rabbit skeletal muscle by affinity chromatography has been characterized. The molecular weight of the native protein as determined by analytical ultracentrifugation and polyacrylamide gel electrophoresis at varying acrylamide concentrations is 76 800 and 82 000, respectively. The protein is asymmetric with frictional and axial ratios of 1.64 and 12. SDS and urea polyacrylamide gel electrophoresis indicate that the native cyclic AMP receptor is composed of two identical subunits of 42 700 molecular weight. The native protein dimer binds 2 moles of cyclic AMP per mole of protein and is active in suppressing activity of isolated catalytic subunits of cyclic AMP-dependent protein kinase. Cyclic GMP receptor protein from bovine lung has been purified using the same affinity chromatography media. Since cyclic nucleotide binding to cyclic GMP-dependent protein kinase does not result in dissociation of regulatory receptor and catalytic phosphotransferase subunits, the cyclic GMP-dependent protein kinase holoenzyme is retained on the column and can be subsequently specifically eluted with cyclic GMP.

Animals↗
PubMed1976

Abnormal microorganisms and cell-mediated immunity in patients with intraoral cancer.

A substantial number of patients with intraoral malignant neoplasms have abnormal bacterial flora of skin, nasopharynx, and oropharynx, without a demonstrable relationship between tumor size, location, or degree of ulceration. Seventeen consecutive patients were studied to determine what relationship, if any, exists between the presence of abnormal microorganisms and the patients' immunological competence. Ten of 17 patients grew potentially pathogenic organisms, and all reacted to specific skin tests used to infer immunological competence. Thus, there appeared to be no relationship between cellular immunity and the presence of abnormal bacteria in patients with intraoral malignant neoplasms.

Bacteria↗
PubMed1976

Intracranial and extracranial nasopharyngeal angiofibroma. A surgical approach.

Two patients with juvenile nasopharyngeal angiofibromas with known or suspected intracranial extension were treated successfully with a surgical procedure. The procedure involves careful preoperative examination with four-vessel carotid angiography followed by preoperative occlusion of the extracranial major feeding vessels. This is followed by craniotomy, direct control of all intracranial feeding vessels, and then total extirpation of the tumor.

Adolescent↗
PubMed1976

Urinary tract changes in obstetric vesico-vaginal fistulae: a report of 216 cases studied by intravenous urography.

Intravenous urographies carried out routinely on 216 cases of vesico-vaginal fistulae were reviewed. All the patients had suffered from urinary incontinence following obstructed labour for periods varying from immediate post-partum period to as long as 35 years with the majority (48%) presenting in the first year of the disease. One hundred and eleven patients (51-4%) showed no urinary tract abnormality. Calyceal abnormality was graded from 1-5 in ascending order of severity. The most frequent abnormality was Grade 1 (or minimal calyceal blunting) found in 75 (71%) of 105 cases showing lesions. Ten patients had non-functioning kidneys. There was no correlation of severity of calyceal grading with duration of the disease. Other notable changes were hydroureter in 75 (34%), medial deviation of the terminal ureters in 21 (9-7%) and bladder calculi in four. The study reveals a high risk of morbidity to the kidneys in patients with vesico-vaginal fistulae and the predominant role of fibrous itssue in tis genesis is postulated.

Adolescent↗
PubMed1975

Adenotonsillectomy in a Jehovah's Witness with blood dyscrasia.

A case is used to illustrate a method of management of three unusual problems all simultaneously appearing in the same patient. Urgent surgical intervention was necessary for a child with a bleeding disorder, but the parents religious doctrine prohibited the use of whole blood or its products. The combined efforts of the legal, medical, and allied medical professionals led to a successful resolution of the patient's multiple problems.

Adenoidectomy↗
PubMed1973

Prevention of galactosamine-induced liver cell necrosis by uridine.

The administration of galactosamine to rats produces dose-dependent liver cell injury. A relatively low dose of galactosamine (200 mg/kg) causes a marked fall in UTP with an accompanying inhibition of RNA and protein synthesis. Uridine will reverse the UTP deficiency and the inhibition of RNA and protein synthesis at any time. The administration of a larger dose of galactosamine (400 mg/kg) produces liver cell necrosis within 12 hours. Although the effects on macromolecular synthesis are very similar with the two doses, cell necrosis distinguishes the reaction of the liver to the larger dose from that to the lower. Uridine will also prevent the development of liver cell necrosis, even if given as late as 3 hours after the galactosamine. This was shown by examination of the changes in serum glutamic oxalocetic transaminase levels and by examination of the histologic changes in the livers. Other purines do not have this protective effect; adenine is unable to prevent liver cell necrosis. As the known biochemical effects of the two doses of galactosamine are very similar during the first 3 hours, the protective effect of uridine seems to imply the existence of an as yet unknown lesion distinguishing the reaction of the liver cell to the larger dose of galactosamine. Uridine must prevent the appearance of this lesion or reverse its development.

Animals↗
PubMedDate not supplied

Racism and health care access: a dialogue with childbearing women.

The rates of low birth weight and preterm delivery are twice as high for African Americans as they are for Whites in the United States. Racism and health care access may be factors in this twofold disparity. To investigate this possibility, we conducted a qualitative study with African American prenatal and postpartum women (N = 14). In 1- to 2-hr interviews, we asked the participants to describe their ability to access health care and their experiences of racism. We then independently and collectively coded the data until consensus (95%) was obtained. Data categories included access to care, treatment, differences in care, stereotypes, and racism. Three themes emerged from the interviews: (a) the pervasiveness of the stereotype of pregnant African American women; (b) a care that is indifferent, inaccessible, and undignified; and (c) the totality of racism. These themes encompass social, political, and economic factors affecting the experiences of childbearing African American families and mandate the need for further investigation and intervention.

Adolescent↗
PubMedDate not supplied

The effects of carcinogenic methylcholanthrene on carbohydrate residues of NK cells.

The present study examines the effect of methylcholanthrene (MCA), a a carcinogenic polycyclic hydrocarbon, on the carbohydrate receptor determinants (RD) on natural killer (NK) cell surface using the bead-coupled lectin assay. Murine NK cells exhibited different degrees of preferential binding to the specific lectins tested. Of the ten lectins tested, five exhibited a positive binding affinity while the remaining five exhibited no or insignificant binding. NK cells bind to beads derivatized with mannose specific lectins: Concanavalin A (Con A), Lens culinaris, and Pisum sativum. NK cells also bind to other lectin beads such as Triticum vulgaris (GalNac) and Vicia villosa (D-GlcNAc). All these lectin beads exhibited greater than 90% adhesion. The underivatized control beads exhibited no NK binding. The NK cells that were exposed to MCA for 2 h demonstrated a significant decrease in lectin bead-cell coupling in a dose dependent manner. MCA (10 micrograms/mL) caused a 17.8%, 40% and 4.7% decrease in binding affinity when introduced to the mannose specific lectins; Con A, L. culinaris and P. sativum beads, respectively. The binding of T. vulgaris and V. villosa to NK cells was inhibited (23.4% and 28%) by MCA treatment. An increase in the dose to 20 micrograms/mL resulted in a greater inhibition in binding affinity towards lectin beads. Con A, 35.3%, L. culinaris, 62.6%, P. sativum, 30.9%, T. vulgaris, 44.2% and V. villosa, 46.2%. The effect of MCA activation and cytotoxic response. Hydrolysis of PI metabolites (PIP and PIP2) cause generation of secondary messenger: inositol-1,4,5-triphosphate and diacylglycerol, both of which elicit an immune response through their products (Ca2+ and PKC) respectively. Identification of the relationship between receptor level, induction of second messenger and cytotoxic activity may resolve the molecular basis of suppression of NK cytotoxicity by MCA and other PAH compounds.

Animals↗
PubMedDate not supplied

Going Dutch? How to make clinical guidelines work: an innovative report from Holland.

This article describes the findings of a recent Dutch enquiry on the translation of modern medical evidence and research into good clinical practice. There is a huge current increase in 'clinical guidelines' for many diseases, but even when reasonably evidence-based, there is little evidence that they positively affect clinical practice and patient care to any great extent. Educational and management issues are as important as the quality of the clinical advice. Patient acceptance factors also need to be considered.

Humans↗